Volume 8, Issue 4
October 1938, pages 249-373
pp 249-265 October 1938
pp 266-279 October 1938
The felspars of the pegmatites of Kodarma have been classified with special reference to their perthitic textures. It has been suggested that there have been at least two distinct periods in the evolution of the felspars of the pegmatites, the first is represented by orthoclase and microcline perthites of the composite ‘vein’ and ‘film’ type and the second by albiteoligoclase of ‘antiperthitic’ and ‘pure’ type. The former phase preceded the latter phase. The felspar of the second phase shows a replacing relation to that of the first phase when the two occur together. These two phases of the generation of felspars may be explained as due to the differentiation of the granitic residue into potash-rich and soda-rich fractions. The origin of the various types of perthitic intergrowths—‘films’, ‘stringers’, ‘veins’, ‘inclusions’ and ‘antiperthitic’ patches—have been discussed on the basis of their textural features, and the rôle of deuteric replacement has been emphasised in the formation of vein-perthites.
pp 280-287 October 1938
pp 288-294 October 1938
pp 295-300 October 1938
The author describes a new species ofEcteinascidia (fam. Clavelinidæ) collected from Bombay. The present species can be distinguished from other existing species by the following characters: the siphonal apertures are 5-lobed; tentacles are of three lengths and about 64 in number; the posterior dorsal languets are long conical and distinct; the transverse muscles completely encircle the pharynx; the internal longitudinal bars have projections comparable to papillæ; the stomach has folds in its walls.
Ten to twelve individuals form a colony, each individual being attached by a peduncle to a basal stolon network. Development is internal, the atrial cavity acting as a brood-pouch, and the young are discharged into the sea as fully developed tadpoles.
pp 301-308 October 1938
An attempt has been made in this paper to study the photosynthetic activity of a number of plant species under optimum yet identical conditions of factor-intensity and to trace the relationship, if any, between the organic materials subsequently formed and the assimilatory influx of carbon dioxide.
Different plant species have different photosynthetic rates, the range of variation from species to species becoming more and more pronounced with advance in age of plants. Such variations under otherwise constant external conditions are discussed with special reference to internal factors.
The water-content of the experimental material no doubt differs from plant to plant but does not follow the same gradation as that maintained by assimilation rate. The chlorophyll content too shows no correlation with the assimilatory efficiency.
There seems to be a fair degree of correlation between the products economised in leaves during their photosynthetic activity and the products stored by the same species towards the close of the life-cycle. Plants economising sugars, proteins, starches and fats in assimilating leaves also store such substances respectively in their storage organs towards the close of their life-cycle.
The photosynthetic rate seems to be related to the nature of the end products accumulating in assimilating leaves. Leaves accumulating simpler sugars have fairly high rates of assimilation while those economising the more complex starches, proteins and fats respectively have to their credit decreasing assimilatory efficiency.
The biochemic constitution of the experimental material as judged by the products economised during assimilation appears to be an important internal factor governing photosynthesis and suggestively explains the phenomenon of photosynthetic specificity in certain groups of crop plants.
pp 309-316 October 1938
In sorghum, a new gene designatedInty is responsible for an extreme reduction in the internodal length, producing Tiny plants. Internodal number is not affected but internodal length only. The wide divergence in internodal length is less graphic in its effect on leaf-sheath length. With reference to the leaf-blade, its length is more affected than its breadth. This gene does not affect the number of whorls on the earhead but has its effect in the panicle having a lesser number and shorter length of secondary panicle branches resulting in fewer spikelets per earhead. Glume size remains practically unaffected. So also ovary and stigma size. The anthers and filaments are reduced in size. The anthers are devoid of pollen. Dwarf plants are therefore usually sterile. Stray pollen grains could be found in some anthers and fertilization by them results in seeds giving true-breeding Tiny plants. The stigmas are very receptive and natural crossing is chronic. Plants heterozygous for the character are the main source of their reproduction. Factorinty is a simple monogenic recessive toInty.
pp 317-323 October 1938
Anthocyanic purple pigment expresses itself in the sorghum plant in various places and at various times. This occurrence could be grouped into specific chains of manifestation. The anther is rarely coloured purple. When it is so coloured, it is one among the following ten places in its chain: plumule, nodal band, axil, auricular junction, leaf-sheath margin, pulvinus of the panicle branches, pedicelled spikelets, glume tips, exposed roots and pericarp of the grain at milky stage. The expression of this purple in freshly emerging anthers is noted in some races of cultivated sorghum, East African and Nigerian in origin, belonging to the groupsS. caudatum, S. coriaceum, S. nigricans, S. elegans, S. Roxburghii, andS. conspicuum. Purple in the anthers occurs in the wild sorghumsS. halepense of the Eu-Sorghum group, andS. versicolor, S. dimidiatum andS. purpureo- sericeum of the Para-Sorghum group. A gene designated Pan is responsible for this expression of purple in the anther. In its absence (Pan) the anther is of the ordinary yellow colour. Pan is a simple dominant to Pan in crosses between African races. Factor Pan behaves in inheritance independently of one of the B factors determining the brown colour of the grain of the Q factor conditioning the colour of the leaf-sheath and of the factor responsible for the production of brown colour in the nucellar layer of the grain. The occurrence of this dominant gene along with other similar dominant pigment genes6,7 in African races and their disappearance in the Indian and other Asiatic races throws light on the origin and evolution of cultivated sorghums.
pp 324-335 October 1938
The application of chlorine from the very beginning of the life-cycle of wheat, brings about a slight depression in dry matter production and an increase in moisture content during their early stages of growth. With advance in age, however, the dry matter accumulation is markedly increased without any appreciable increase in water content.
Plants supplied with chlorine twenty days after germination have the maximum dry matter yield. Relative growth rate as well as net assimilation rate are also accelerated.
The treated plants do not show any marked effect on their shoot length although the assimilatory surface is increased beyond the control. The roots, on the other hand, in spite of a diminution in length, exhibit a greater lateral ramification and dry matter production.
Chlorine-treated plants have a larger percentage ear formation maximum values being obtained in case where this element is supplied twenty days after germination.
The accumulation of carbohydrates as also the diastatic activity are greater in the treated plants as compared to the control ones.
Growth of plants at successive stages of the life-cycle appears to be determined by both the age and the factor for chlorine a change in either bringing about a variation in dry matter production.
The greatest physiological need and hence the maximum augmentative efficiency of this element is found at the period (twenty days after germination in the present case) when plants are showing active growth and differentiation.
pp 336-366 October 1938
The author expresses his thanks to his sister-in-law Mrs. use Randhawa for so kindly translating German literature, and to Professor E. N. Transeau for his kindness in examining some of the new species and sending his valuable papers, and Dr. M. 0. P. Iyengar for his helpful suggestions and criticism.
pp 367-372 October 1938
The hydrolysis of the proteins of Bengal gram has been followed by subjecting the whole meal to peptic, trypsic and pepticcum tryptic digestions. It is shown that pepsin releases predominantly polypeptides with a complexity of about 7.
Trypsin records a digestibility of 70 per cent, in the case of total proteins and globulins, and only 44 per cent, in the case of whole meal, whereas pepsin records about 70 per cent, in the case of globulins and total proteins, and about 80 per cent, in the case of whole meal. By the successive action of trypsin and pepsin, the total proteins are digested to the extent of nearly 89 per cent., the same being the case with the whole meal.
A close study of the tables and graphs reveals that as far as peptic digestion is concerned, there is practically no difference in the digestibilities of total proteins and globulins when present in the seed material or after isolation. In the case of tryptic digestion however, the whole meal records a much lower digestibility.
pp 373-373 October 1938 Erratum