Prototypes of black wattle tannins and their stereochemistry
- Authors: Drewes, Siegfried Ernst
- Date: 1963
- Subjects: Tannins -- Anthocyanidis Stereochemistry
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4460 , http://hdl.handle.net/10962/d1011437
- Description: A number of interrelated flavonoid compounds, present in trace quantities in mature black wattle (Acacia mearnsii De Wild) bark, have been isolated and identified for the first time. They include a) the resorcinol-pyrogallol analogues, (+)-leuco-robinetinidin (7,5',4',5'-tetrahydroxyflavan-3,4-diol), dihydrorobinetin (7,5',4',5'-tetrahydroxyflavan-3-ol-4-one) and robtein (2',4',5,4,5- pentahydroxychalcone) and b) the resorcinol-catechol analogues, (+)-leuco-fisetinidin (7,3',4'-trihydroxyflavan-3,4-diol), fustin (7,3',4'-trihydroxyflavan-3-ol-4-one), (-)-fisetinidol (7,3',4'trihydroxyflavan- 3-ol), butein (2',4',3,4-tetrahydroxychalcone) and butin (7,5',4'-trihydroxyflavan-4-one). In addition, two flavonol glycosides, myricitrin (3,5,7,3',4',5'-hexahydroxyflavone-3-rhamnoside ) and quercitrin (5,5,7,5',4'-pentahydroxyflavone-3-rhamnoside), which belong to the phloroglucinol-pyrogallol and phloroglucinolcatechol class of flavonoids respectively, were isolated from immature bark. These represent the only glycosides isolated hitherto from wattle bark or heartwood extracts. Summary, p. i.
- Full Text:
- Date Issued: 1963
- Authors: Drewes, Siegfried Ernst
- Date: 1963
- Subjects: Tannins -- Anthocyanidis Stereochemistry
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4460 , http://hdl.handle.net/10962/d1011437
- Description: A number of interrelated flavonoid compounds, present in trace quantities in mature black wattle (Acacia mearnsii De Wild) bark, have been isolated and identified for the first time. They include a) the resorcinol-pyrogallol analogues, (+)-leuco-robinetinidin (7,5',4',5'-tetrahydroxyflavan-3,4-diol), dihydrorobinetin (7,5',4',5'-tetrahydroxyflavan-3-ol-4-one) and robtein (2',4',5,4,5- pentahydroxychalcone) and b) the resorcinol-catechol analogues, (+)-leuco-fisetinidin (7,3',4'-trihydroxyflavan-3,4-diol), fustin (7,3',4'-trihydroxyflavan-3-ol-4-one), (-)-fisetinidol (7,3',4'trihydroxyflavan- 3-ol), butein (2',4',3,4-tetrahydroxychalcone) and butin (7,5',4'-trihydroxyflavan-4-one). In addition, two flavonol glycosides, myricitrin (3,5,7,3',4',5'-hexahydroxyflavone-3-rhamnoside ) and quercitrin (5,5,7,5',4'-pentahydroxyflavone-3-rhamnoside), which belong to the phloroglucinol-pyrogallol and phloroglucinolcatechol class of flavonoids respectively, were isolated from immature bark. These represent the only glycosides isolated hitherto from wattle bark or heartwood extracts. Summary, p. i.
- Full Text:
- Date Issued: 1963
The influence of temperature in the ecology of the intermediate host snails of Schistosoma and Fasciola (Trematoda) in southern Rhodesia
- Authors: Shiff, Clive Julian
- Date: 1963
- Subjects: Schistosoma , Schistosomiasis , Fasciola , Snails -- Zimbabwe , Trematoda
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5881 , http://hdl.handle.net/10962/d1013208
- Description: The influence of temperature on the bionomics of Bulinus (Physopsis) globosus, Biomphalaria pfeifferi and Lymnaea natalensis has been studied both in the laboratory under controlled conditions and in the field under normal seasonal influences. Field studies were carried out in two different localities, one a semi-permanent pond and the other a temporary waterbody. For this purpose a sampling implement was developed. The results show the seasonal progression of these populations both with respect to estimated numbers and the size distribution of the snails. The rate of actual increase at different seasons was calculated for the three species where the data were sufficient. In the laboratory the snails were maintained at various temperatures, other conditions being kept standard. Daily records of mortality and fecundity of various cohorts reared from the egg stage enabled the compilation of life tables fof the speciesand from these data were calcualted the intrinsic rate of natural increase and other parameters. Effects of crowding in aquaria were studied. From the data obtained in the laboratory it was possible to predict the distribution and population potential for each species for snail of various environmental conditions. These predictions were, in fact, confirmed by field observation.
- Full Text:
- Date Issued: 1963
- Authors: Shiff, Clive Julian
- Date: 1963
- Subjects: Schistosoma , Schistosomiasis , Fasciola , Snails -- Zimbabwe , Trematoda
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5881 , http://hdl.handle.net/10962/d1013208
- Description: The influence of temperature on the bionomics of Bulinus (Physopsis) globosus, Biomphalaria pfeifferi and Lymnaea natalensis has been studied both in the laboratory under controlled conditions and in the field under normal seasonal influences. Field studies were carried out in two different localities, one a semi-permanent pond and the other a temporary waterbody. For this purpose a sampling implement was developed. The results show the seasonal progression of these populations both with respect to estimated numbers and the size distribution of the snails. The rate of actual increase at different seasons was calculated for the three species where the data were sufficient. In the laboratory the snails were maintained at various temperatures, other conditions being kept standard. Daily records of mortality and fecundity of various cohorts reared from the egg stage enabled the compilation of life tables fof the speciesand from these data were calcualted the intrinsic rate of natural increase and other parameters. Effects of crowding in aquaria were studied. From the data obtained in the laboratory it was possible to predict the distribution and population potential for each species for snail of various environmental conditions. These predictions were, in fact, confirmed by field observation.
- Full Text:
- Date Issued: 1963
A comparative study of the catechin components in the barks of wattle species related to Acacia Mernsii
- Authors: Maihs, Edwin Alfred
- Date: 1962
- Subjects: Wattles (Plants) Acacia mearnsii Acacia
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4482 , http://hdl.handle.net/10962/d1012793
- Description: The distribution of flavonoid constituents in the barks of Acacia mearnsii De Wild.(black wattle) , A· decurens Willd. (green wattle), A. dealbata Link.(silver wattle) and A. pycnantha Benth.(golden wattle) has been studied. Bark extracts of the four wattle species have been fractionated into low molecular weight fractions containing mainly catechins and other low molecular weight constituents, and high molecular weight fractions containing the bulk of the polymerized tannins. The low molecular weight fractions have been further fractionated by "preparative paper chromatography". (-)-Robinetinidol, (-)-7:3': 4': 5'-tetrahydroxy flavan- 3-ol, a new naturally occurring catechin, (+)-catechin and (+)-gallocatechin have been isolated from the barks of A. mearnsii, A. dealbata and A. pycnantha. (-)-Epicatechin and (-)-epigallocatechin have been identified in the bark extracts of A. dealbata and A. pycnantha, but appeared to be absent in the barks of A. mearnsii and A. decurrens. (-)-Epicatechin has been isolated fron A. dealbata, and both (-}-epicatechin and (-)-epigallocatechin were isolated from A. pycnantha. (-)-Epicatechin gallate, (-)-epigallocatechin gallate and gallic acid were isolated from A. pycnantha only. These three constituents appeared to be absent in the barks of the three other wattle species. (-)-Epigallocatechin, (-)-epicatechin gallate and (-)-epigallocatechin gallate which were not available for direct comparison, were subsequently isolated from green tea where they are present as major phenolic constituents. A method for the quantitative estimation of polyphenolic substances on two dimensional paper chromatograms has been developed, and a photoelectric densitometer constructed. Two spray reagents, ammoniacal silver nitrate and bisdiazotised benzidine, were found to give straight line relationships of instrument deflection against log concentration for flavonoid substances. This estimation method for the first time supplied means for a detailed study of the concentration of catechin constituents in the bark extracts of A. mearnsii, A. decurrens, A. dealbata, A. pycnantha and of A. mearnsii x A. decurrens hybrids. The concentration of catechin constituents has been shown to vary considerably between species whereas variation within species was small. In the latter respect silver wattle is an exception. Taxonomic significance may possibly be attached to the distribution of catechin constituents in the bark of the four Acacia species. The concentration of (-)-robinetinidol, which appears to be the characteristic compound of these Acacias, progressively decreases in the sequence black-, black x green hybrid, green-, silver- and golden wattle, while the number of catechin constituents of the "phloroglucinol series" increases in the same sequence. It thus appears, that by the examination of their bark components, a differentiation between species of a subgenera may be possible. Two tannins, constituents D and B, which are related to the leuco-anthocyanidins (flavan-3:4-diols) have been found in the barks of the four wattle species. One of the two, constituent D, was isolated in a pure form from the barks of A. mearnsii and A. pycnantha. Constituent D was found to generate robinetinidin and an orange pigment, the structure of which has not yet been fully identified. Compound D and its acetyl- and methoxyl derivatives did not crystallize. From the results of alkaline-, acidic- and enzymatic degradations, colour reactions and light-absorption studies, combustion analysis of the compound and its derivatives and molecular weight estimations, constituent D is surmised to be a dimer of 7:3': 4': 5'-tetrahydroxyflavan-3:4-diol (leuco-robinetinidin), The isolation of this complex leuco-anthocyanidin tannin represents the first isolation of a flavonoid tannin from commercial vegetable tannin sources. The second tannin obtained from the bark of A.mearnsii, "constituent B" appears to consist of two overlapping substances, which have not yet been separated. The tannin (B) was found to have an average molecular weight of 676 and it is considered likely that both substances may be dimolecular. On heating with mineral acid robinetinidin, fisetinidin and an orange pigment are generated, the pigment being identical with the pigment generated from constituent D. It may therefore be assumed that "Constituent B" consists of a mixture of complex leuco-robinetinidins and leucofisetinidins. The distribution of complex leuco-anthocyanidins in the bark extracts of Acacia mearnsii, A. decurrens, A. dealbata and A. pycnantha has been examined. A correlation between the distribution of leuco-anthocyanidins in the bark of the four wattle species, and accepted systematics, does not, apparently, exist.
- Full Text:
- Date Issued: 1962
- Authors: Maihs, Edwin Alfred
- Date: 1962
- Subjects: Wattles (Plants) Acacia mearnsii Acacia
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4482 , http://hdl.handle.net/10962/d1012793
- Description: The distribution of flavonoid constituents in the barks of Acacia mearnsii De Wild.(black wattle) , A· decurens Willd. (green wattle), A. dealbata Link.(silver wattle) and A. pycnantha Benth.(golden wattle) has been studied. Bark extracts of the four wattle species have been fractionated into low molecular weight fractions containing mainly catechins and other low molecular weight constituents, and high molecular weight fractions containing the bulk of the polymerized tannins. The low molecular weight fractions have been further fractionated by "preparative paper chromatography". (-)-Robinetinidol, (-)-7:3': 4': 5'-tetrahydroxy flavan- 3-ol, a new naturally occurring catechin, (+)-catechin and (+)-gallocatechin have been isolated from the barks of A. mearnsii, A. dealbata and A. pycnantha. (-)-Epicatechin and (-)-epigallocatechin have been identified in the bark extracts of A. dealbata and A. pycnantha, but appeared to be absent in the barks of A. mearnsii and A. decurrens. (-)-Epicatechin has been isolated fron A. dealbata, and both (-}-epicatechin and (-)-epigallocatechin were isolated from A. pycnantha. (-)-Epicatechin gallate, (-)-epigallocatechin gallate and gallic acid were isolated from A. pycnantha only. These three constituents appeared to be absent in the barks of the three other wattle species. (-)-Epigallocatechin, (-)-epicatechin gallate and (-)-epigallocatechin gallate which were not available for direct comparison, were subsequently isolated from green tea where they are present as major phenolic constituents. A method for the quantitative estimation of polyphenolic substances on two dimensional paper chromatograms has been developed, and a photoelectric densitometer constructed. Two spray reagents, ammoniacal silver nitrate and bisdiazotised benzidine, were found to give straight line relationships of instrument deflection against log concentration for flavonoid substances. This estimation method for the first time supplied means for a detailed study of the concentration of catechin constituents in the bark extracts of A. mearnsii, A. decurrens, A. dealbata, A. pycnantha and of A. mearnsii x A. decurrens hybrids. The concentration of catechin constituents has been shown to vary considerably between species whereas variation within species was small. In the latter respect silver wattle is an exception. Taxonomic significance may possibly be attached to the distribution of catechin constituents in the bark of the four Acacia species. The concentration of (-)-robinetinidol, which appears to be the characteristic compound of these Acacias, progressively decreases in the sequence black-, black x green hybrid, green-, silver- and golden wattle, while the number of catechin constituents of the "phloroglucinol series" increases in the same sequence. It thus appears, that by the examination of their bark components, a differentiation between species of a subgenera may be possible. Two tannins, constituents D and B, which are related to the leuco-anthocyanidins (flavan-3:4-diols) have been found in the barks of the four wattle species. One of the two, constituent D, was isolated in a pure form from the barks of A. mearnsii and A. pycnantha. Constituent D was found to generate robinetinidin and an orange pigment, the structure of which has not yet been fully identified. Compound D and its acetyl- and methoxyl derivatives did not crystallize. From the results of alkaline-, acidic- and enzymatic degradations, colour reactions and light-absorption studies, combustion analysis of the compound and its derivatives and molecular weight estimations, constituent D is surmised to be a dimer of 7:3': 4': 5'-tetrahydroxyflavan-3:4-diol (leuco-robinetinidin), The isolation of this complex leuco-anthocyanidin tannin represents the first isolation of a flavonoid tannin from commercial vegetable tannin sources. The second tannin obtained from the bark of A.mearnsii, "constituent B" appears to consist of two overlapping substances, which have not yet been separated. The tannin (B) was found to have an average molecular weight of 676 and it is considered likely that both substances may be dimolecular. On heating with mineral acid robinetinidin, fisetinidin and an orange pigment are generated, the pigment being identical with the pigment generated from constituent D. It may therefore be assumed that "Constituent B" consists of a mixture of complex leuco-robinetinidins and leucofisetinidins. The distribution of complex leuco-anthocyanidins in the bark extracts of Acacia mearnsii, A. decurrens, A. dealbata and A. pycnantha has been examined. A correlation between the distribution of leuco-anthocyanidins in the bark of the four wattle species, and accepted systematics, does not, apparently, exist.
- Full Text:
- Date Issued: 1962
An investigation into the effects of ant control on scale insect populations (Homoptera, Coccoidea) of citrus trees in the Eastern Cape Province, South Africa
- Authors: Brettell, J H
- Date: 1962
- Subjects: Scale insects -- South Africa Insect pests -- Biological control
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5838 , http://hdl.handle.net/10962/d1009700
- Description: In order that the citrus industry in South Africa may be commercially developed to the greatest possible extent it is of importance that certain basic ecological problems should be investigated. Until the complex relationships between the host plant, the insect pests and their parasites and predators are known, the results of applications of either chemical or biological control must be largely a matter of chance. A certain amount of rather generalised work in this connection has already been done in South Africa, principally by Carnegie (1955), Smithers (1953) and Whitehead (1948) in the Eastern Cape Province and by Steyn (1954) in the Transvaal. The first three of these workers were content to determine which species of insects occurred in citrus orchards and made some attempts to study the biology of certain predators. Steyn went a little further when he correlated ant activity with scale insect infestations. Without doubt the most economically important insect pests of citrus are the scale insects (Homoptera: Coccoidea). Introduction, p. 1.
- Full Text:
- Date Issued: 1962
- Authors: Brettell, J H
- Date: 1962
- Subjects: Scale insects -- South Africa Insect pests -- Biological control
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5838 , http://hdl.handle.net/10962/d1009700
- Description: In order that the citrus industry in South Africa may be commercially developed to the greatest possible extent it is of importance that certain basic ecological problems should be investigated. Until the complex relationships between the host plant, the insect pests and their parasites and predators are known, the results of applications of either chemical or biological control must be largely a matter of chance. A certain amount of rather generalised work in this connection has already been done in South Africa, principally by Carnegie (1955), Smithers (1953) and Whitehead (1948) in the Eastern Cape Province and by Steyn (1954) in the Transvaal. The first three of these workers were content to determine which species of insects occurred in citrus orchards and made some attempts to study the biology of certain predators. Steyn went a little further when he correlated ant activity with scale insect infestations. Without doubt the most economically important insect pests of citrus are the scale insects (Homoptera: Coccoidea). Introduction, p. 1.
- Full Text:
- Date Issued: 1962
Construction of a wide-frequency range double heterodyne conductance bridge and its use in the investigation of polarisation errors in conductance measurements
- Authors: Govinden, Herby Silvester
- Date: 1961
- Subjects: Electrodynamics Electrolytes -- Conductivity
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5522 , http://hdl.handle.net/10962/d1012074
- Description: (1) Developments in a.c. conductance techniques during the past ninety years have been reviewed, and a brief outline is given of the older theories regarding electrolytic polarisation. (2) A conductance bridge - incorporating the double heterodyne principle - has been constructed, capable of giving resistance readings to an accuracy of 0.01% over a range of frequencies covering the best part of 100 kc/s. It has also been found possible to calibrate the oscillator so that frequency settings can be guaranteed to an accuracy of , at least, 0.1% in the range: 2 kc/S to 50 kc/S. (3) The Wheatstone Bridge Network has been slightly modified to enable measurements at the high frequencies. (4) Resistances in the measuring arm of the bridge have been calibrated 'in situ' by the method of intercomparison. (5) A brief description is given of the modern theories regarding electrode processes and modern methods of eliminating electrode effects. (6) Two types of conductance cells, with bright Pt electrodes, have been used to carry out measurements on potassium chloride solutions: (a) Thomas- Gledhill Cell (b) Nichol-Fuoss Cell. The latter incorporates concentric, cylindrical electrodes with the lead to the outer electrode acting as an electrical shield for the lead to the inner electrode. This cell was constructed and used for the first time in this laboratory. (7) From resistance-frequency graphs plotted, it is shown that the Jones and Christian extrapolation procedure cannot be applied (with any degree of confidence) to obtain the true resistance, when measurements are effected over an extended range of frequencies. (8) The method of resistance-reactance diagrams is discussed and applied to various networks of resistances and capacitances. (9) By drawing resistance-reactance diagrams for the experimental readings obtained, equivalent circuits have been derived - for all the solutions investigated in the N-F cell, and for the approx. O.OlD solution in the T-G cell - which approximate to cell behaviour in the range: 500 c/s to 75 kc/s. The less concentrated solutions in the T-G cell show peculiar behaviour at the high frequencies. (10) Probable reasons are advanced for deviations from linearity on resistance-frequency graphs. (11) A new method is proposed for determining the true resistance of solutions measured in cells of the N-F type. Summary, p. 166-167.
- Full Text:
- Date Issued: 1961
- Authors: Govinden, Herby Silvester
- Date: 1961
- Subjects: Electrodynamics Electrolytes -- Conductivity
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5522 , http://hdl.handle.net/10962/d1012074
- Description: (1) Developments in a.c. conductance techniques during the past ninety years have been reviewed, and a brief outline is given of the older theories regarding electrolytic polarisation. (2) A conductance bridge - incorporating the double heterodyne principle - has been constructed, capable of giving resistance readings to an accuracy of 0.01% over a range of frequencies covering the best part of 100 kc/s. It has also been found possible to calibrate the oscillator so that frequency settings can be guaranteed to an accuracy of , at least, 0.1% in the range: 2 kc/S to 50 kc/S. (3) The Wheatstone Bridge Network has been slightly modified to enable measurements at the high frequencies. (4) Resistances in the measuring arm of the bridge have been calibrated 'in situ' by the method of intercomparison. (5) A brief description is given of the modern theories regarding electrode processes and modern methods of eliminating electrode effects. (6) Two types of conductance cells, with bright Pt electrodes, have been used to carry out measurements on potassium chloride solutions: (a) Thomas- Gledhill Cell (b) Nichol-Fuoss Cell. The latter incorporates concentric, cylindrical electrodes with the lead to the outer electrode acting as an electrical shield for the lead to the inner electrode. This cell was constructed and used for the first time in this laboratory. (7) From resistance-frequency graphs plotted, it is shown that the Jones and Christian extrapolation procedure cannot be applied (with any degree of confidence) to obtain the true resistance, when measurements are effected over an extended range of frequencies. (8) The method of resistance-reactance diagrams is discussed and applied to various networks of resistances and capacitances. (9) By drawing resistance-reactance diagrams for the experimental readings obtained, equivalent circuits have been derived - for all the solutions investigated in the N-F cell, and for the approx. O.OlD solution in the T-G cell - which approximate to cell behaviour in the range: 500 c/s to 75 kc/s. The less concentrated solutions in the T-G cell show peculiar behaviour at the high frequencies. (10) Probable reasons are advanced for deviations from linearity on resistance-frequency graphs. (11) A new method is proposed for determining the true resistance of solutions measured in cells of the N-F type. Summary, p. 166-167.
- Full Text:
- Date Issued: 1961
Gold fineness in hydrothermal ores : an investigation into the distribution of gold and silver in Southern Rhodesian gold ores
- Authors: Eales, Hugh V
- Date: 1961
- Subjects: Hydrothermal deposits -- Zimbabwe , Gold ores -- Zimbabwe , Silver ores -- Zimbabwe , Silver mines and mining -- Zimbabwe
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5077 , http://hdl.handle.net/10962/d1014887
- Description: This investigation is concerned with primary variations in the silver content of gold which occurs in hydrothermal deposits, particularly those of hypothermal character which are found in Basement rocks in Southern Rhodesia. The nature of the gold produced by a number of different mines has been studied by reference to production data, and microscope techniques as well as gold and silver assays have been used to determine and to explain the variations in gold fineness. The literature does not contain a great deal of information which is relevant to this topic, but an attempt has been made here to summarize the more important contributions by different writers. From this it emerges that the interpretations given by different investigators are in conflict and that paradoxes may arise when efforts are made to explain observed variations in fineness in terms of certain generalizations which have become entrenched in the literaure. In particular, it is shown that falling temperature alone cannot account for the occurrence of silver-rich gold in certain deposits. The Gwanda district of Southern Rhodesia has been selected as a typical gold belt, and the variation in fineness in 150 producers is described. The deposits are hypothermal in character, and the average fineness of the gold is high but variable, but in a small proportion the fineness is low. It is shown that the nature of the host rock and the distance of a deposit from the granite contact appear to have no influence on the fineness of the gold and that there is no zonal arrangement of fineness values. There is a suggestion that diversity of mineral species in any particular area may be accompanied by rather wide fluctuations in the gold fineness. The variations of fineness in eight typical Southern Rhodesian deposits are studied in detail, by analysis of production data, by assaying specimens of the ore and by the examination of polished specimens of gold-bearing ore. Briefer reference is made to two other deposits in the territory, and to deposits in other countries which appear to bear out the conclusions reached in this section. It emerges that there are two factors which can commonly be correlated with variations in fineness. The first of these is the grade of the ore: high-grade ore generally contains purer gold than low-grade ore. Secondly, the textural evidence indicates that gold which separates relatively early in the paragenesis contains more silver than that which is deposited in the final stages of metallization. A general survey which draws on the literature as well as on the writer's examinations of deposits in the territory indicates that, in general, gold which is associated with late-stage minerals such as tellurides, antimony, bismuth and bismuthinite is silver-poor. Gold associated with galena may be either silver-rich or silver-poor, whereas gold which is of the same age as chalcopyrite or sphalerite is very frequently rich in silver. The difficulty which is encountered in establishing the age of gold which is intimately associated with pyrite and arsenopyrite renders uncertain the correlation between fineness and age of gold in these latter cases. There are, however, indications that gold which is truly contemporaneous with either pyrite or arsenopyrite is silver-rich. In the discussion, the objections to the common practice of singling out temperature as the most potent factor controlling gold fineness are listed. Chief amongst these objections is the fact that gold does not in all deposits increase in fineness with increasing depth: examples are quoted where fineness was found to decrease as deeper levels of the ore body were exploited. It is shown that there is no consistent relationship between the size of gold grains and their silver content. It is the writer's conclusion that in hydrothermal deposits in this territory the high fineness of the gold is due to increasing solubility of silver in the ore fluids in the late states, and that where hydrothermal deposits are characterized by gold with low average fineness, an unusually large proportion of the gold has been deposited early in the paragenotic sequence. In the majority of hypothermal deposits, however, the bulk of tho gold separates late in the sequence and the fineness is accordingly high. It is believed that the relationship which exists between fineness and tenor in many deposits is due to protracted crystallization of gold in those portions of the ore body which remained permeable to the latest stages. These portions of the ore body, which represent either valuable ore shoots or ore shoots in miniature, are likely to contain gold of variable character, but the average silver content will be low because a large proportion of the gold is "late" gold. The factors which might cause epithermal gold to have a lower fineness than mesothermal or hypothermal gold are briefly discussed. Some possible applications of this study are indicated in the final chapter. It is claimed that records of gold fineness might constitute a valuable addition to mill records. Tentative suggestions are made regarding a method whereby the approaching exhaustion of a deposit might in some cases be predicted. With regard to the origin of the gold in the Witwatersrand sediments, it is pointed out that the modified placer hypothesis is not fully equipped to explain certain of the variations in the composition of the gold.
- Full Text:
- Date Issued: 1961
- Authors: Eales, Hugh V
- Date: 1961
- Subjects: Hydrothermal deposits -- Zimbabwe , Gold ores -- Zimbabwe , Silver ores -- Zimbabwe , Silver mines and mining -- Zimbabwe
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5077 , http://hdl.handle.net/10962/d1014887
- Description: This investigation is concerned with primary variations in the silver content of gold which occurs in hydrothermal deposits, particularly those of hypothermal character which are found in Basement rocks in Southern Rhodesia. The nature of the gold produced by a number of different mines has been studied by reference to production data, and microscope techniques as well as gold and silver assays have been used to determine and to explain the variations in gold fineness. The literature does not contain a great deal of information which is relevant to this topic, but an attempt has been made here to summarize the more important contributions by different writers. From this it emerges that the interpretations given by different investigators are in conflict and that paradoxes may arise when efforts are made to explain observed variations in fineness in terms of certain generalizations which have become entrenched in the literaure. In particular, it is shown that falling temperature alone cannot account for the occurrence of silver-rich gold in certain deposits. The Gwanda district of Southern Rhodesia has been selected as a typical gold belt, and the variation in fineness in 150 producers is described. The deposits are hypothermal in character, and the average fineness of the gold is high but variable, but in a small proportion the fineness is low. It is shown that the nature of the host rock and the distance of a deposit from the granite contact appear to have no influence on the fineness of the gold and that there is no zonal arrangement of fineness values. There is a suggestion that diversity of mineral species in any particular area may be accompanied by rather wide fluctuations in the gold fineness. The variations of fineness in eight typical Southern Rhodesian deposits are studied in detail, by analysis of production data, by assaying specimens of the ore and by the examination of polished specimens of gold-bearing ore. Briefer reference is made to two other deposits in the territory, and to deposits in other countries which appear to bear out the conclusions reached in this section. It emerges that there are two factors which can commonly be correlated with variations in fineness. The first of these is the grade of the ore: high-grade ore generally contains purer gold than low-grade ore. Secondly, the textural evidence indicates that gold which separates relatively early in the paragenesis contains more silver than that which is deposited in the final stages of metallization. A general survey which draws on the literature as well as on the writer's examinations of deposits in the territory indicates that, in general, gold which is associated with late-stage minerals such as tellurides, antimony, bismuth and bismuthinite is silver-poor. Gold associated with galena may be either silver-rich or silver-poor, whereas gold which is of the same age as chalcopyrite or sphalerite is very frequently rich in silver. The difficulty which is encountered in establishing the age of gold which is intimately associated with pyrite and arsenopyrite renders uncertain the correlation between fineness and age of gold in these latter cases. There are, however, indications that gold which is truly contemporaneous with either pyrite or arsenopyrite is silver-rich. In the discussion, the objections to the common practice of singling out temperature as the most potent factor controlling gold fineness are listed. Chief amongst these objections is the fact that gold does not in all deposits increase in fineness with increasing depth: examples are quoted where fineness was found to decrease as deeper levels of the ore body were exploited. It is shown that there is no consistent relationship between the size of gold grains and their silver content. It is the writer's conclusion that in hydrothermal deposits in this territory the high fineness of the gold is due to increasing solubility of silver in the ore fluids in the late states, and that where hydrothermal deposits are characterized by gold with low average fineness, an unusually large proportion of the gold has been deposited early in the paragenotic sequence. In the majority of hypothermal deposits, however, the bulk of tho gold separates late in the sequence and the fineness is accordingly high. It is believed that the relationship which exists between fineness and tenor in many deposits is due to protracted crystallization of gold in those portions of the ore body which remained permeable to the latest stages. These portions of the ore body, which represent either valuable ore shoots or ore shoots in miniature, are likely to contain gold of variable character, but the average silver content will be low because a large proportion of the gold is "late" gold. The factors which might cause epithermal gold to have a lower fineness than mesothermal or hypothermal gold are briefly discussed. Some possible applications of this study are indicated in the final chapter. It is claimed that records of gold fineness might constitute a valuable addition to mill records. Tentative suggestions are made regarding a method whereby the approaching exhaustion of a deposit might in some cases be predicted. With regard to the origin of the gold in the Witwatersrand sediments, it is pointed out that the modified placer hypothesis is not fully equipped to explain certain of the variations in the composition of the gold.
- Full Text:
- Date Issued: 1961
Pineapples in the Eastern Cape : a study of the farm economy and marketing patterns
- Authors: Strauss, Conrad B
- Date: 1961
- Subjects: Pineapple industry -- South Africa -- Eastern Cape , Agriculture -- Economic aspects -- South Africa , Farm produce -- Marketing
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1103 , http://hdl.handle.net/10962/d1013318
- Description: The major objective of this study was to seek a better knowledge and greater understanding of the factors associated with successful pineapple farming in the Eastern Cape Region of the Union of South Africa. As no previous · investigation equally representative of commercial pineapple farming patterns in the Eastern Cape has been made, this study can be regarded as a pilot survey of the labour structures, rates of production, combination of enterprises; marketing channels and the suitability of various districts in the region of study for the production of pineapples. In addition, the history of the pineapple in South Africa will be traced briefly, and the position the Union holds as a supplier of pineapples on the world market, will be investigated. the importance of the Eastern Cape as a producer of pineapples in South Africa is well known, but is also unequivocally illustrated by the information in Table 1. According to estimates made by the Division of Economics and Markets for 1955/56 season, no less than 86.5 percent of the total acreage planted to pineapples in South Africa, was located in this area. Bathurst, East London and Albany, three of the six districts included in the estimate, were particularly prominent. Taken together, they cultivated more than three-quarters of the total area planted to pineapples in the Eastern Cape, and nearly 70 per cent of the total for South Africa. The remaining quarter of the area cultivated in the Eastern Cape was located in the districts of Peddie, Komgha and Alexandria.
- Full Text:
- Date Issued: 1961
- Authors: Strauss, Conrad B
- Date: 1961
- Subjects: Pineapple industry -- South Africa -- Eastern Cape , Agriculture -- Economic aspects -- South Africa , Farm produce -- Marketing
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1103 , http://hdl.handle.net/10962/d1013318
- Description: The major objective of this study was to seek a better knowledge and greater understanding of the factors associated with successful pineapple farming in the Eastern Cape Region of the Union of South Africa. As no previous · investigation equally representative of commercial pineapple farming patterns in the Eastern Cape has been made, this study can be regarded as a pilot survey of the labour structures, rates of production, combination of enterprises; marketing channels and the suitability of various districts in the region of study for the production of pineapples. In addition, the history of the pineapple in South Africa will be traced briefly, and the position the Union holds as a supplier of pineapples on the world market, will be investigated. the importance of the Eastern Cape as a producer of pineapples in South Africa is well known, but is also unequivocally illustrated by the information in Table 1. According to estimates made by the Division of Economics and Markets for 1955/56 season, no less than 86.5 percent of the total acreage planted to pineapples in South Africa, was located in this area. Bathurst, East London and Albany, three of the six districts included in the estimate, were particularly prominent. Taken together, they cultivated more than three-quarters of the total area planted to pineapples in the Eastern Cape, and nearly 70 per cent of the total for South Africa. The remaining quarter of the area cultivated in the Eastern Cape was located in the districts of Peddie, Komgha and Alexandria.
- Full Text:
- Date Issued: 1961
The border region : a geographical study of land utilization
- Authors: Board, Christopher
- Date: 1961
- Subjects: Land use -- South Africa -- Cape of Good Hope , Vegetation and climate -- South Africa -- Cape of Good Hope , Geology -- South Africa -- Cape of Good Hope , Cape of Good Hope (South Africa) -- Environmental conditions
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4884 , http://hdl.handle.net/10962/d1013512
- Description: From Summary: This is a geographical study of land use in the Eastern Cape Province. The land use pattern, although related closely to the features of the natural environment, is perhaps even more closely related to the spatial variations of the man-made environment, particularly to the disposition of the different racial groups with their different cultures and economies, and to the kaleidoscopic character of the settlement pattern.
- Full Text:
- Date Issued: 1961
- Authors: Board, Christopher
- Date: 1961
- Subjects: Land use -- South Africa -- Cape of Good Hope , Vegetation and climate -- South Africa -- Cape of Good Hope , Geology -- South Africa -- Cape of Good Hope , Cape of Good Hope (South Africa) -- Environmental conditions
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4884 , http://hdl.handle.net/10962/d1013512
- Description: From Summary: This is a geographical study of land use in the Eastern Cape Province. The land use pattern, although related closely to the features of the natural environment, is perhaps even more closely related to the spatial variations of the man-made environment, particularly to the disposition of the different racial groups with their different cultures and economies, and to the kaleidoscopic character of the settlement pattern.
- Full Text:
- Date Issued: 1961
The geology of the Miami Mica field (Urungwe District)
- Authors: Wiles, J W
- Date: 1961
- Subjects: Geology -- Zimbabwe -- Urungwe District , Mines and mineral resources -- Zimbabwe -- Urungwe District , Mica -- Zimbabwe -- Urungwe District
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5071 , http://hdl.handle.net/10962/d1013503
- Description: [Preface] The detailed geological survey of the country described in this bulletin commenced in 1953 and was completed in 1956 with the mapping of 1,480 square miles of country. Information is supplied on 227 mines which produced mica alone or both mica and beryl, and 134 mines which produced only beryl. In addition, wolfram, gold, graphite, kyanite and rutile deposits and mines are described. Mineral outputs are given up to end of 1959. The field mapping and writing of the bulletin is entirely the work of Mr. Wiles. Mapping of the Field has established that, with a few exceptions, a metamorphic control has operated in the development of economic sheet mica and has led to the conclusion that very many of these pegmatites are composite bodies which have derived their material from two sources: one metamorphic and the other igneous. This conclusion was arrived at after a detailed petrographic investigation of the metamorphic rocks. The map at the end of this bulletin was drawn by Mr.A. H. Barrie and the diagrams are largely the work of Mr. D. O. L. Levy. Chemical analyses are by Messrs. A. J. Radford and E. Golding and were made in the Geological Survey Laboratory. Some of the photographs are by H. J. Cotterel of the Geological Survey while the remainder were taken by the Planning and Technical Services of the Federal Ministry of Home Affairs (formerly the Federal Information Department). It gives me pleasure to acknowledge the assistance and facilities offered the Department by mining men and residents in the district.
- Full Text:
- Date Issued: 1961
- Authors: Wiles, J W
- Date: 1961
- Subjects: Geology -- Zimbabwe -- Urungwe District , Mines and mineral resources -- Zimbabwe -- Urungwe District , Mica -- Zimbabwe -- Urungwe District
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5071 , http://hdl.handle.net/10962/d1013503
- Description: [Preface] The detailed geological survey of the country described in this bulletin commenced in 1953 and was completed in 1956 with the mapping of 1,480 square miles of country. Information is supplied on 227 mines which produced mica alone or both mica and beryl, and 134 mines which produced only beryl. In addition, wolfram, gold, graphite, kyanite and rutile deposits and mines are described. Mineral outputs are given up to end of 1959. The field mapping and writing of the bulletin is entirely the work of Mr. Wiles. Mapping of the Field has established that, with a few exceptions, a metamorphic control has operated in the development of economic sheet mica and has led to the conclusion that very many of these pegmatites are composite bodies which have derived their material from two sources: one metamorphic and the other igneous. This conclusion was arrived at after a detailed petrographic investigation of the metamorphic rocks. The map at the end of this bulletin was drawn by Mr.A. H. Barrie and the diagrams are largely the work of Mr. D. O. L. Levy. Chemical analyses are by Messrs. A. J. Radford and E. Golding and were made in the Geological Survey Laboratory. Some of the photographs are by H. J. Cotterel of the Geological Survey while the remainder were taken by the Planning and Technical Services of the Federal Ministry of Home Affairs (formerly the Federal Information Department). It gives me pleasure to acknowledge the assistance and facilities offered the Department by mining men and residents in the district.
- Full Text:
- Date Issued: 1961
The spectrochemical determination of certain minor trace elements in plant material
- Authors: Eve, Desmond John
- Date: 1961
- Subjects: Trace elements Spectrum analysis Plants -- Analysis Plants -- Effect of trace elements on Trace elements in agriculture
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4469 , http://hdl.handle.net/10962/d1011773
- Description: A study has been made of three organic complexing reagents , namely dithizone, oxine and cupferron with a view to developing suitable methods for the separation and concentration of Zn, Co, Ni, Pb, Cu, Mn, Ti , V and Mo prior to the spectrometric determination of their concentrations. In particular the influence of pH on the chloroform extraction of ditihizonates, oxinates and cupferrates from aqueous tartrate and citrate solutions and the separation of iron by oxine extraction has been investigated. The development of a method for the chemical concentration and spectrcgraphic determination of Zn, Co, Ni, Pb, Ti, V and Mo is described and the possibility of determining Nn and Cu flame photometrically as part of the analysis scheme is demonstrated. A specially designed slide rule for the calculation of spectrographic results is described. A direct reading spectrometric method for the determination of Zn, Pb and Cu in plant material is presented. The analysis of plant ash for zinc using the 2138 . 6A spectrum line has been studied and a simple, rapid analysis method is described.
- Full Text:
- Date Issued: 1961
- Authors: Eve, Desmond John
- Date: 1961
- Subjects: Trace elements Spectrum analysis Plants -- Analysis Plants -- Effect of trace elements on Trace elements in agriculture
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4469 , http://hdl.handle.net/10962/d1011773
- Description: A study has been made of three organic complexing reagents , namely dithizone, oxine and cupferron with a view to developing suitable methods for the separation and concentration of Zn, Co, Ni, Pb, Cu, Mn, Ti , V and Mo prior to the spectrometric determination of their concentrations. In particular the influence of pH on the chloroform extraction of ditihizonates, oxinates and cupferrates from aqueous tartrate and citrate solutions and the separation of iron by oxine extraction has been investigated. The development of a method for the chemical concentration and spectrcgraphic determination of Zn, Co, Ni, Pb, Ti, V and Mo is described and the possibility of determining Nn and Cu flame photometrically as part of the analysis scheme is demonstrated. A specially designed slide rule for the calculation of spectrographic results is described. A direct reading spectrometric method for the determination of Zn, Pb and Cu in plant material is presented. The analysis of plant ash for zinc using the 2138 . 6A spectrum line has been studied and a simple, rapid analysis method is described.
- Full Text:
- Date Issued: 1961
Insecticide resistance in the blue tick, Boophilus Decoloratus Koch, in South Africa
- Authors: Whitehead, G B
- Date: 1960
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5897 , http://hdl.handle.net/10962/d1013426
- Description: The work described in this dissertation was undertaken in an attempt to obtain a better understanding of the causes and relationships of insecticide resistance in Blue Tick, Boophilus decoloratus Koch, which has become an acute problem in some localities of the country. The work was undertaken at the Research Department of African Explosives and Chemical Industries Limited over a period of six years from 1953 to 1958. An attempt has been made to keep up to date with the published literature on the various aspects of these investigations up until the end of 1958. Information gained from the literature subsequent to end of 1958 has been made use of but it has not been possible for a number of reasons to follow all recent developments in the various aspects of insecticide resistance published during 1959. In the execution of this work assistance has been obtained from colleagues better equipped in the field of organic chemistry, biochemistry and statistics, than the author. Where information so gained has been used it has been duly acknowledged. Considerable assistance was rendered by laboratory assistants who were responsible for performing the considerable amount of routine collection, breeding and testing of the biological material. The blue tick is not a convenient experimental organism for studies on insecticide resistance. Even with the best facilities the tick cannot be bred satisfactorily and in consequence all supplies had to be collected from naturally-occurring populations. Although this had decided advantages in some aspects of the work, a great deal of useful information might have been obtained if certain strains of ticks could have been maintained. The lack of a standard sensitive reference strain has been a considerable disadvantage which could not be overcome and which has influenced the manner in which this work has been carried out. Because the tick could not be bred artificially the work could only be undertaken with unfed larvae and fully engorged adult females . Larvae are extremely small and in consequence could only be handled in batches while the fully engorged female is sluggish and contains a large quantity of semi-digested mammalian blood which invariably interfered with chemical or biochemical studies.
- Full Text:
- Date Issued: 1960
- Authors: Whitehead, G B
- Date: 1960
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5897 , http://hdl.handle.net/10962/d1013426
- Description: The work described in this dissertation was undertaken in an attempt to obtain a better understanding of the causes and relationships of insecticide resistance in Blue Tick, Boophilus decoloratus Koch, which has become an acute problem in some localities of the country. The work was undertaken at the Research Department of African Explosives and Chemical Industries Limited over a period of six years from 1953 to 1958. An attempt has been made to keep up to date with the published literature on the various aspects of these investigations up until the end of 1958. Information gained from the literature subsequent to end of 1958 has been made use of but it has not been possible for a number of reasons to follow all recent developments in the various aspects of insecticide resistance published during 1959. In the execution of this work assistance has been obtained from colleagues better equipped in the field of organic chemistry, biochemistry and statistics, than the author. Where information so gained has been used it has been duly acknowledged. Considerable assistance was rendered by laboratory assistants who were responsible for performing the considerable amount of routine collection, breeding and testing of the biological material. The blue tick is not a convenient experimental organism for studies on insecticide resistance. Even with the best facilities the tick cannot be bred satisfactorily and in consequence all supplies had to be collected from naturally-occurring populations. Although this had decided advantages in some aspects of the work, a great deal of useful information might have been obtained if certain strains of ticks could have been maintained. The lack of a standard sensitive reference strain has been a considerable disadvantage which could not be overcome and which has influenced the manner in which this work has been carried out. Because the tick could not be bred artificially the work could only be undertaken with unfed larvae and fully engorged adult females . Larvae are extremely small and in consequence could only be handled in batches while the fully engorged female is sluggish and contains a large quantity of semi-digested mammalian blood which invariably interfered with chemical or biochemical studies.
- Full Text:
- Date Issued: 1960
The frontier in South African English verse : 1820-1927
- Authors: Taylor, Avis Elizabeth
- Date: 1960
- Subjects: South African poetry (English) -- 19th century , South African literature (English) -- History and criticism , South Africa -- In literature
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2318 , http://hdl.handle.net/10962/d1013347
- Description: The concept of a distinctively South African poetry in English has been, and still is, derided as a "pipe dream" as part of the fallacy which stems from the desire for a "national" literature. In 1955, for instance, C.J. Harvey (in an article containing much common sense as well as sound literary judgment) denounced the self-conscious hunting for "Local Colour" which engrosses so many South African writers. Harvey claimed: "Our civilization is not "South African", except in trivial details, it is Western European, and more specifically as far as poetry written in English is concerned, English ... ". There is a serious error of emphasis here. It would be more accurate to say that our ancestors brought Western European civilization to this continent. To imagine that this civilisation has not undergone and is not still constantly suffering a subtle but far-reaching metamorphosis in Africa would be to fly in the face of reality. White South Africans do not only carry the same identity-card but they can be distinguished from Frenchmen, Englishmen or Irishmen by more than "trivial details". This thesis is an examination of some af the earliest English written in southern Africa, particularly of the verse produced by our poetasters and near-poets. It attempts, during the course of this examination, to call attention to a few of the more significant changes which have arisen as the result of the importation of Western civilsation to an African frontier. Further I hope to show some at the varying ways in which these differences affected the white pioneer and how this has been reflected in our verse since pioneering times. In this sense the Frontier may be thought of as the background against which South African English writers developed certain characteristic traits. Intro., p. 1-2.
- Full Text:
- Date Issued: 1960
- Authors: Taylor, Avis Elizabeth
- Date: 1960
- Subjects: South African poetry (English) -- 19th century , South African literature (English) -- History and criticism , South Africa -- In literature
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2318 , http://hdl.handle.net/10962/d1013347
- Description: The concept of a distinctively South African poetry in English has been, and still is, derided as a "pipe dream" as part of the fallacy which stems from the desire for a "national" literature. In 1955, for instance, C.J. Harvey (in an article containing much common sense as well as sound literary judgment) denounced the self-conscious hunting for "Local Colour" which engrosses so many South African writers. Harvey claimed: "Our civilization is not "South African", except in trivial details, it is Western European, and more specifically as far as poetry written in English is concerned, English ... ". There is a serious error of emphasis here. It would be more accurate to say that our ancestors brought Western European civilization to this continent. To imagine that this civilisation has not undergone and is not still constantly suffering a subtle but far-reaching metamorphosis in Africa would be to fly in the face of reality. White South Africans do not only carry the same identity-card but they can be distinguished from Frenchmen, Englishmen or Irishmen by more than "trivial details". This thesis is an examination of some af the earliest English written in southern Africa, particularly of the verse produced by our poetasters and near-poets. It attempts, during the course of this examination, to call attention to a few of the more significant changes which have arisen as the result of the importation of Western civilsation to an African frontier. Further I hope to show some at the varying ways in which these differences affected the white pioneer and how this has been reflected in our verse since pioneering times. In this sense the Frontier may be thought of as the background against which South African English writers developed certain characteristic traits. Intro., p. 1-2.
- Full Text:
- Date Issued: 1960
The junior secondary course of the Cape Province and the dull-normal child : (a pilot study based on research in the Border area and the North-Eastern districts)
- Authors: Loots, Francois Jacobus
- Date: 1960
- Subjects: Education, Secondary -- South Africa -- Cape of Good Hope , Children -- Intelligence levels , Children with mental disabilities -- Education -- South Africa -- Cape of Good Hope
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1994 , http://hdl.handle.net/10962/d1013501
- Description: [Aims of Dissertation and Investigation, p. ix-x] The aim of this dissertation is to analyse and evaluate the results of the new junior secondary course in respect of the dull-normal child ... How well did the junior secondary course succeed in meeting the needs of the dull-normal child? That is the question which this investigation will attempt to answer.
- Full Text:
- Date Issued: 1960
- Authors: Loots, Francois Jacobus
- Date: 1960
- Subjects: Education, Secondary -- South Africa -- Cape of Good Hope , Children -- Intelligence levels , Children with mental disabilities -- Education -- South Africa -- Cape of Good Hope
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1994 , http://hdl.handle.net/10962/d1013501
- Description: [Aims of Dissertation and Investigation, p. ix-x] The aim of this dissertation is to analyse and evaluate the results of the new junior secondary course in respect of the dull-normal child ... How well did the junior secondary course succeed in meeting the needs of the dull-normal child? That is the question which this investigation will attempt to answer.
- Full Text:
- Date Issued: 1960
Ionospheric studies of the solar eclipse 25 December, 1954
- Authors: McElhinny, M W
- Date: 1959
- Subjects: Ionosphere -- Research , Solar eclipses
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5531 , http://hdl.handle.net/10962/d1012869
- Description: Since the Kennelly- Heaviside hypothesis in 1902 of the existence of a partially conducting layer in the upper atmosphere was proved to be true by the experiments of APPLETON and BARNETT (1925) and BREIT and TUVE (1926), this region has become known as the ionosphere. The ionosphere was soon discovered to consist of, not one but several layers (Fig. 1) (i) A layer at a height of just over 100 km. called the E layer. (ii) A layer at a height of approximately 300km. called the F₂ layer. (iii) A layer at a height of approximately 200 km. called the F₁ layer; this layer differs from the other two in that it is only present during the day time in Summer. (iv) Occasional intense reflections from a height of about 100 km. are found - these cannot be attributed to the normal E layer and have received the name "Sporadic E". The presence of two E layers (E₁ and E₂) has been suggested by HALLIDAY (1936) and BEST and RATCLIFFE (l978) but until recently most workers still seem to attribute these reflections to Sporadic E. Recent measurement by rockets of the electron density at E layer heights still do not confirm whether such bifurcation exists in the E region. The diurnal and seasonal variations of the first three layers indicate that the sun is the chief agent in their production. It is generally agreed that these layers consist of ionised molecules or atoms and free electrons produced by radiation from the sun. The origin of Sporadic E ionisation is still obscure, but it is thought that these sudden increases in ionisation which occur in E layer heights are due to passing meteors. Recently it has also been suggested by SEDDON, PICKAR and JACKSON (1954) from rocket measurements that Sporadic E might be due to a steep electron density gradient above the B layer.
- Full Text:
- Date Issued: 1959
- Authors: McElhinny, M W
- Date: 1959
- Subjects: Ionosphere -- Research , Solar eclipses
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5531 , http://hdl.handle.net/10962/d1012869
- Description: Since the Kennelly- Heaviside hypothesis in 1902 of the existence of a partially conducting layer in the upper atmosphere was proved to be true by the experiments of APPLETON and BARNETT (1925) and BREIT and TUVE (1926), this region has become known as the ionosphere. The ionosphere was soon discovered to consist of, not one but several layers (Fig. 1) (i) A layer at a height of just over 100 km. called the E layer. (ii) A layer at a height of approximately 300km. called the F₂ layer. (iii) A layer at a height of approximately 200 km. called the F₁ layer; this layer differs from the other two in that it is only present during the day time in Summer. (iv) Occasional intense reflections from a height of about 100 km. are found - these cannot be attributed to the normal E layer and have received the name "Sporadic E". The presence of two E layers (E₁ and E₂) has been suggested by HALLIDAY (1936) and BEST and RATCLIFFE (l978) but until recently most workers still seem to attribute these reflections to Sporadic E. Recent measurement by rockets of the electron density at E layer heights still do not confirm whether such bifurcation exists in the E region. The diurnal and seasonal variations of the first three layers indicate that the sun is the chief agent in their production. It is generally agreed that these layers consist of ionised molecules or atoms and free electrons produced by radiation from the sun. The origin of Sporadic E ionisation is still obscure, but it is thought that these sudden increases in ionisation which occur in E layer heights are due to passing meteors. Recently it has also been suggested by SEDDON, PICKAR and JACKSON (1954) from rocket measurements that Sporadic E might be due to a steep electron density gradient above the B layer.
- Full Text:
- Date Issued: 1959
Linkage in extra-sensory perception
- Authors: Marsh, Maurice Clement
- Date: 1959
- Subjects: Telepathy , Extrasensory perception
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3215 , http://hdl.handle.net/10962/d1012840
- Description: The aims of this investigation were firstly to find whether 371 subjects, mainly students at Rhodes University, would be able to reproduce target drawings made 470 miles away by an agent in Cape Town, by means of General Extra-Sensory Perception; secondly, to find whether any association existed between any such hit scoring ability shown and personality ratings derived from a battery of personality test material; and thirdly, to find whether providing the subjects with material designed to link them more closely with the agent would increase their scoring rate. The 17,440 drawings returned by the subjects were randomised, and scored against a randomised set of 100 drawings consisting of 50 which had actually been used as targets, intermixed with 50 that were equal in difficulty but which had not been used as targets, and which were inserted merely as controls. Three independent judges assessed the subjects' drawings, and awarded hits in terms of title, shape and association. In the crucial title hits highly significant deviations in favour of the experimental target drawings were found, the control series of drawings showing no such effects. It was found that the subjects' hits were distributed evenly throughout the whole 25 day period of the experiment for each target, and showed no tendency to occur more frequently in the week a particular drawing was being used as a target than in the other weeks when it was not. When the subjects were divided into a high scoring and low-scoring group in terms of their E.S. P. abiility, the high- scoring group proved to be significantly more extraverted (as measured by the Bernreuter B3I scale) than the low- scoring group, confirming a relationship previously reported by Humphrey. In addition the data showed several other relationships, predicted by the work of previous experimenters, although these did not reach the .01 level of statistical significance. To assess the effect of the Linkage Material the subjects were divided into an experimental and a control group. The Experimental Group was supplied with correct Linkage Material, the Control Group with incorrect Linkage Material, which they were led to believe was correct . The two sets of Linkage Material were equated in all other respects. The Experimental Group showed significant improvements in scoring rate when supplied with a photograph and description of the agent, and a probably significant improvement when supplied with squares of handkerchief which had previously belonged to him. When supplied with squares of colour, also appearing on the agent's target sheets, no significant increase in scoring rate took place on the target drawings, but a significant decrease occurred in hits scored on the control targets. By contrast no consistent significant fluctuations were shown by Control Group Subjects, leading to the conclusion that the correctness of the Linkage Material was a factor contributing to its effectiveness. A qualitative examination of the hits scored by the subjects revealed that they tended to reproduce the concepts depicted by the target drawings, rather than the actual shapes drawn by the agent, suggesting that the hits were being produced by a telepathic process rather than a clairvoyant one. The results of the experiment suggest that the subjects were assisted by the Linkage Material to gain access to the agent's mind as a whole, and not to particular items in it. This throws doubt on the correctness of Whately Carington's Association Theory of Telepathy, which the experiment was designed to test.
- Full Text:
- Date Issued: 1959
- Authors: Marsh, Maurice Clement
- Date: 1959
- Subjects: Telepathy , Extrasensory perception
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3215 , http://hdl.handle.net/10962/d1012840
- Description: The aims of this investigation were firstly to find whether 371 subjects, mainly students at Rhodes University, would be able to reproduce target drawings made 470 miles away by an agent in Cape Town, by means of General Extra-Sensory Perception; secondly, to find whether any association existed between any such hit scoring ability shown and personality ratings derived from a battery of personality test material; and thirdly, to find whether providing the subjects with material designed to link them more closely with the agent would increase their scoring rate. The 17,440 drawings returned by the subjects were randomised, and scored against a randomised set of 100 drawings consisting of 50 which had actually been used as targets, intermixed with 50 that were equal in difficulty but which had not been used as targets, and which were inserted merely as controls. Three independent judges assessed the subjects' drawings, and awarded hits in terms of title, shape and association. In the crucial title hits highly significant deviations in favour of the experimental target drawings were found, the control series of drawings showing no such effects. It was found that the subjects' hits were distributed evenly throughout the whole 25 day period of the experiment for each target, and showed no tendency to occur more frequently in the week a particular drawing was being used as a target than in the other weeks when it was not. When the subjects were divided into a high scoring and low-scoring group in terms of their E.S. P. abiility, the high- scoring group proved to be significantly more extraverted (as measured by the Bernreuter B3I scale) than the low- scoring group, confirming a relationship previously reported by Humphrey. In addition the data showed several other relationships, predicted by the work of previous experimenters, although these did not reach the .01 level of statistical significance. To assess the effect of the Linkage Material the subjects were divided into an experimental and a control group. The Experimental Group was supplied with correct Linkage Material, the Control Group with incorrect Linkage Material, which they were led to believe was correct . The two sets of Linkage Material were equated in all other respects. The Experimental Group showed significant improvements in scoring rate when supplied with a photograph and description of the agent, and a probably significant improvement when supplied with squares of handkerchief which had previously belonged to him. When supplied with squares of colour, also appearing on the agent's target sheets, no significant increase in scoring rate took place on the target drawings, but a significant decrease occurred in hits scored on the control targets. By contrast no consistent significant fluctuations were shown by Control Group Subjects, leading to the conclusion that the correctness of the Linkage Material was a factor contributing to its effectiveness. A qualitative examination of the hits scored by the subjects revealed that they tended to reproduce the concepts depicted by the target drawings, rather than the actual shapes drawn by the agent, suggesting that the hits were being produced by a telepathic process rather than a clairvoyant one. The results of the experiment suggest that the subjects were assisted by the Linkage Material to gain access to the agent's mind as a whole, and not to particular items in it. This throws doubt on the correctness of Whately Carington's Association Theory of Telepathy, which the experiment was designed to test.
- Full Text:
- Date Issued: 1959
The executive government of the Cape of Good Hope, 1825-54
- Authors: Fryer, Alan Kenneth
- Date: 1959
- Subjects: Cape of Good Hope (South Africa) -- History -- 1795-1872
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2604 , http://hdl.handle.net/10962/d1011896
- Description: The study of administrative processes is a relaltively new one both in the field of history and sociology. In both disciplines what is required is study of the sructure and growth of adminstrative systems and of the impact of administrative action on the community it seeks to serve and which it often provokes. In the field of history, Professor F. Tout in his chapters on administrative history ... gave new vitality and understanding to medieval studies. In the main, South African history, though probably not more so than other Commonwealth countries, has been less fortunate. Preface, p. 1.
- Full Text:
- Date Issued: 1959
- Authors: Fryer, Alan Kenneth
- Date: 1959
- Subjects: Cape of Good Hope (South Africa) -- History -- 1795-1872
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2604 , http://hdl.handle.net/10962/d1011896
- Description: The study of administrative processes is a relaltively new one both in the field of history and sociology. In both disciplines what is required is study of the sructure and growth of adminstrative systems and of the impact of administrative action on the community it seeks to serve and which it often provokes. In the field of history, Professor F. Tout in his chapters on administrative history ... gave new vitality and understanding to medieval studies. In the main, South African history, though probably not more so than other Commonwealth countries, has been less fortunate. Preface, p. 1.
- Full Text:
- Date Issued: 1959
The photo-fluorescence properties of some organic materials
- Authors: Cameron, Antony John Wesley
- Date: 1959
- Subjects: Hydrocarbons -- Spectra -- Fluorescence , Organic compounds , Energy transfer
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5514 , http://hdl.handle.net/10962/d1010041 , Hydrocarbons -- Spectra -- Fluorescence , Organic compounds , Energy transfer
- Description: In this thesis I have given an account of the experimental work carried out by me at Rhodes University from the beginning of 1954 to the end of 1955, and the analysis of the results which was completed during the following two years, 1956 and 1957. The dissertation is divided into two sections; Part I deals with the photo fluorescence spectra of a large group of organic compounds, and Part 2 describes an investigation of the photo-fluorescence properties of and energy transfer in liquid organic solutions.
- Full Text:
- Date Issued: 1959
- Authors: Cameron, Antony John Wesley
- Date: 1959
- Subjects: Hydrocarbons -- Spectra -- Fluorescence , Organic compounds , Energy transfer
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5514 , http://hdl.handle.net/10962/d1010041 , Hydrocarbons -- Spectra -- Fluorescence , Organic compounds , Energy transfer
- Description: In this thesis I have given an account of the experimental work carried out by me at Rhodes University from the beginning of 1954 to the end of 1955, and the analysis of the results which was completed during the following two years, 1956 and 1957. The dissertation is divided into two sections; Part I deals with the photo fluorescence spectra of a large group of organic compounds, and Part 2 describes an investigation of the photo-fluorescence properties of and energy transfer in liquid organic solutions.
- Full Text:
- Date Issued: 1959
The transport system of the Border : a study of transport and communications in the Border region of the Cape Province with special reference to the effect of transport on the economic and commercial development of the region
- Authors: Smith, Hugh Hamilton
- Date: 1959
- Subjects: Transportation -- South Africa -- Eastern Cape , Harbors -- South Africa -- East London , Railroads -- South Africa -- Eastern Cape , Transportation, Automotive -- South Africa -- Eastern Cape , Communication and traffic -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1122 , http://hdl.handle.net/10962/d1018721
- Description: Transport undoubtedly occupies a most important place in the economic and commercial life of all countries. In this respect South Africa is no exception, and very briefly, the principal economic functions of transport are enumerated below. 1. Transport establishes communication between consumers and the producers of goods or services. 2. Transport facilitates the movement of persons between the place where they live and the place where they work - usually this is a daily procedure, but in South Africa it also entails the movement of large numbers of Natives from the Native Reserves to work for some months at a time either in the gold mines or in the several urban areas of the Union. 3. Transport makes geographical specialization possible, for agricultural or mineral resources will only be exploited, or specialized industries established, in a particular area, if the commodities produced can be transported to other parts of a country, or the world; and other capital and consumer goods brought to the producers living in the area of specialized production. 4. Transport faciitates industrial production because, of raw materials which come from many sources. Furthermore, transport enables the finished products of industry to be distributed to the markets in which they are sold. In all these cases, the efficiency of transport has to be measured not only in terms of its cost, but also in terms of its efficiency, which includes, inter alia, the time taken, the frequency of services, the safety of goods and passengers while in transit and the provision of various special services, such as the provision by railway undertakings of private siding facilities. This thesis will be divided into five parts, the first dealing with the technical and commercial development of the Buffalo Harbour. It has been decided to deal with the Harbour first because, not only has it been the focal point of the transport system of the Border Region since the latter part of the nineteenth century, but it has dominated the economic and commercial development of East London, as well as that of the Border Region as a whole. The second part deals with the evolution of the railway system from the 166 mile long East London and Queenstown Railway, to the present 1,110 miles of the Cape Eastern System. This historical chapter is followed by an analysis of the traffic of the Cape Eastern System. Part Three deals with the theory, practice, and economic consequences, of railway rating policy. Part Four is a detailed analysis of the goods traffic forwarded from, and received at East London in the period from 1st April, 1953 to 31st March, 1956. Part Five deals with roads and road transport. Finally, certain conclusions are offered, based on the significant points revealed by the investigation on which this thesis is based. In this thesis the theory of transport will not be dealt with in detail for it is essentially a factual account of the development of the transport system of the Border Region and an analysis of the present situation. It has unfortunately not been possible to make in this thesis a study of railway finance or railway economics with regard to the Cape Eastern System, for the data upon which to base such an investigation are not available for the Cape Eastern System in isolation. No attempt will be made to assess either the technical or the operating efficiency of the railway system for not only would this require more data than are available, but also a technical knowledge not possessed by the writer.
- Full Text:
- Date Issued: 1959
- Authors: Smith, Hugh Hamilton
- Date: 1959
- Subjects: Transportation -- South Africa -- Eastern Cape , Harbors -- South Africa -- East London , Railroads -- South Africa -- Eastern Cape , Transportation, Automotive -- South Africa -- Eastern Cape , Communication and traffic -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1122 , http://hdl.handle.net/10962/d1018721
- Description: Transport undoubtedly occupies a most important place in the economic and commercial life of all countries. In this respect South Africa is no exception, and very briefly, the principal economic functions of transport are enumerated below. 1. Transport establishes communication between consumers and the producers of goods or services. 2. Transport facilitates the movement of persons between the place where they live and the place where they work - usually this is a daily procedure, but in South Africa it also entails the movement of large numbers of Natives from the Native Reserves to work for some months at a time either in the gold mines or in the several urban areas of the Union. 3. Transport makes geographical specialization possible, for agricultural or mineral resources will only be exploited, or specialized industries established, in a particular area, if the commodities produced can be transported to other parts of a country, or the world; and other capital and consumer goods brought to the producers living in the area of specialized production. 4. Transport faciitates industrial production because, of raw materials which come from many sources. Furthermore, transport enables the finished products of industry to be distributed to the markets in which they are sold. In all these cases, the efficiency of transport has to be measured not only in terms of its cost, but also in terms of its efficiency, which includes, inter alia, the time taken, the frequency of services, the safety of goods and passengers while in transit and the provision of various special services, such as the provision by railway undertakings of private siding facilities. This thesis will be divided into five parts, the first dealing with the technical and commercial development of the Buffalo Harbour. It has been decided to deal with the Harbour first because, not only has it been the focal point of the transport system of the Border Region since the latter part of the nineteenth century, but it has dominated the economic and commercial development of East London, as well as that of the Border Region as a whole. The second part deals with the evolution of the railway system from the 166 mile long East London and Queenstown Railway, to the present 1,110 miles of the Cape Eastern System. This historical chapter is followed by an analysis of the traffic of the Cape Eastern System. Part Three deals with the theory, practice, and economic consequences, of railway rating policy. Part Four is a detailed analysis of the goods traffic forwarded from, and received at East London in the period from 1st April, 1953 to 31st March, 1956. Part Five deals with roads and road transport. Finally, certain conclusions are offered, based on the significant points revealed by the investigation on which this thesis is based. In this thesis the theory of transport will not be dealt with in detail for it is essentially a factual account of the development of the transport system of the Border Region and an analysis of the present situation. It has unfortunately not been possible to make in this thesis a study of railway finance or railway economics with regard to the Cape Eastern System, for the data upon which to base such an investigation are not available for the Cape Eastern System in isolation. No attempt will be made to assess either the technical or the operating efficiency of the railway system for not only would this require more data than are available, but also a technical knowledge not possessed by the writer.
- Full Text:
- Date Issued: 1959
A statistical study of the errors involved in the sampling and chemical analysis of soils and plants, with particular reference to citrus and pineapples
- Steyn, Willem Johannes Abraham
- Authors: Steyn, Willem Johannes Abraham
- Date: 1958
- Subjects: Soil chemistry , Plants -- Analysis , Soils -- Analysis
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4506 , http://hdl.handle.net/10962/d1013291
- Description: 1. Accurate and reproducible methods for the determination of N and acid- extractable P in soils are described. The variations in N, P, and K found by intensive sampling of three different soil types are presented. 3. Suggestions for the adequate sampling of soils for various purposes arc given. 4. A study is presented of the preparative stages in leaf analysis (washing, drying, grinding and storage) as applied to citrus and pineapple leaf material. Likely errors are pointed out and procedures whereby these may be minimised are described. 5. A reliable wet-ashing procedure for obtaining leaf solutions is described. 6. Accurate and reproducible methods for the determination of total N, P,. K, Ca, Mg, Na, Fe, Mn, Zn and Cu in citrus and pineapple leaves are presented. 7. It is shown that diurnal variations in nutrient concentrations occur in citrus and pineapple leaves. 8. The variations in N, P, K, Ca, Mg, Na, Fe, Mn, Zn and Cu, occurring from tree to tree in 3 different Navel orange blocks are presented. It is shown that if all these elements are to be represented . to within 10% of the mean values on a 19 : 1 probability level, all the trees in the blocks would have to be sampled. Reasonable sampling procedures for various purposes are suggested. 9. The variations in N, P, K, Ca, Mg, Fe, Mn, Zn and Cu, occurring in 3 different Cayenne pineapple plantations are presented and described. Suitable sampling procedures are suggested.
- Full Text:
- Date Issued: 1958
- Authors: Steyn, Willem Johannes Abraham
- Date: 1958
- Subjects: Soil chemistry , Plants -- Analysis , Soils -- Analysis
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4506 , http://hdl.handle.net/10962/d1013291
- Description: 1. Accurate and reproducible methods for the determination of N and acid- extractable P in soils are described. The variations in N, P, and K found by intensive sampling of three different soil types are presented. 3. Suggestions for the adequate sampling of soils for various purposes arc given. 4. A study is presented of the preparative stages in leaf analysis (washing, drying, grinding and storage) as applied to citrus and pineapple leaf material. Likely errors are pointed out and procedures whereby these may be minimised are described. 5. A reliable wet-ashing procedure for obtaining leaf solutions is described. 6. Accurate and reproducible methods for the determination of total N, P,. K, Ca, Mg, Na, Fe, Mn, Zn and Cu in citrus and pineapple leaves are presented. 7. It is shown that diurnal variations in nutrient concentrations occur in citrus and pineapple leaves. 8. The variations in N, P, K, Ca, Mg, Na, Fe, Mn, Zn and Cu, occurring from tree to tree in 3 different Navel orange blocks are presented. It is shown that if all these elements are to be represented . to within 10% of the mean values on a 19 : 1 probability level, all the trees in the blocks would have to be sampled. Reasonable sampling procedures for various purposes are suggested. 9. The variations in N, P, K, Ca, Mg, Fe, Mn, Zn and Cu, occurring in 3 different Cayenne pineapple plantations are presented and described. Suitable sampling procedures are suggested.
- Full Text:
- Date Issued: 1958
Contributions to the biology, anatomy and physiology of Opisthophthalmus Latimanus & other scorpions
- Authors: Alexander, Anne Joy
- Date: 1958
- Subjects: Scorpions -- South Africa , Scorpions -- Anatomy , Scorpions -- Physiology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5891 , http://hdl.handle.net/10962/d1013375
- Description: [From Introduction] For many years the problem of interrelationships within the Arthropoda and, indeed, the origin of the Phylum itself have been of interest to many zoologists. It was felt, for reasons which will be given later, that one of the studies which might throw some light on this matter is that of the neuromuscular physiology of arachnid appendages. Consequently it was proposed that the work which is reported here should be primarily concerned with this problem. As in so many cases involving live animals, both the experimental subjects and the experimenter gradually managed to change the direction in which work was proceeding and the result is that only a preliminary attack has been made on the original problem, while most of the material submitted here deals either with functional anatomy or with biological-cum-behavioural characteristics of the experimental animal. Thus it was found that to develop experimental preparations for neuro-muscular studies, it was necessary to work out the anatomy of the muscles and nerves of the appendages used; but this it is not enough. For these nerves and muscles are part of a functional complex which operates as a unit and have therefore to be studied in relation to the structures that they move. Considerations at this level, in fact, carried the study to the plane of functional anatomy. Furthermore it was recognised that even the comprehension of a limb as a functional complex cannot be acquired in isolation. All structures have an evolutionary history and in any consideration of functional anatomy this history must be taken into account - even if the consideration requires extension to the problem of the origin of the group immediately under study.
- Full Text:
- Date Issued: 1958
Contributions to the biology, anatomy and physiology of Opisthophthalmus Latimanus & other scorpions
- Authors: Alexander, Anne Joy
- Date: 1958
- Subjects: Scorpions -- South Africa , Scorpions -- Anatomy , Scorpions -- Physiology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5891 , http://hdl.handle.net/10962/d1013375
- Description: [From Introduction] For many years the problem of interrelationships within the Arthropoda and, indeed, the origin of the Phylum itself have been of interest to many zoologists. It was felt, for reasons which will be given later, that one of the studies which might throw some light on this matter is that of the neuromuscular physiology of arachnid appendages. Consequently it was proposed that the work which is reported here should be primarily concerned with this problem. As in so many cases involving live animals, both the experimental subjects and the experimenter gradually managed to change the direction in which work was proceeding and the result is that only a preliminary attack has been made on the original problem, while most of the material submitted here deals either with functional anatomy or with biological-cum-behavioural characteristics of the experimental animal. Thus it was found that to develop experimental preparations for neuro-muscular studies, it was necessary to work out the anatomy of the muscles and nerves of the appendages used; but this it is not enough. For these nerves and muscles are part of a functional complex which operates as a unit and have therefore to be studied in relation to the structures that they move. Considerations at this level, in fact, carried the study to the plane of functional anatomy. Furthermore it was recognised that even the comprehension of a limb as a functional complex cannot be acquired in isolation. All structures have an evolutionary history and in any consideration of functional anatomy this history must be taken into account - even if the consideration requires extension to the problem of the origin of the group immediately under study.
- Full Text:
- Date Issued: 1958