Volume 64, Issue 4
October 1966, pages 169-230
pp 169-175 October 1966
Chemical and optical study of the green sodic pyroxene from a tinguaite dyke of the Harohalli area show that it is aegirine, rich in NaFe+3Si2O6 molecules (71%) having Nβ=1·776,γ−α=0·047, X Λ C=4–7°, 2Va=68°–73° and pleochroic with X=olive green, Y=pale green and Z=brown. The calculated chemical composition on the basis of 6 oxygen atoms is (Na, Ca, K)0.99 (Fe+3, Ti, Fe+2, Mn, Mg, [Al]0.98 Si2O6) which corresponds very closely with the ideal formula XYSi2O6.
pp 176-181 October 1966
InCatla fingerlings, the hepatic cells have two types of nuclei—round and oval, and phagocytes similar to those of mammalian liver are present. Histochemical localisation of bile reveals that it is present in the same cells that store glycogen, but bile is not present in all the glycogen-storing hepatic cells.
In pancreas the exocrine and the endocrine portions are completely separate from each other. The acinous exocrine cells lie dispersed in the liver, while the endocrine cells are attached to the intestine. The latter are differentiated into three types—α and β, as in most other vertebrates, and a D-type discovered by the author here, has so far been reported only in higher vertebrates.
pp 182-189 October 1966
In the light of the above discussion, it appears that the parasites and their hosts form a biotype which is both exclusive and interchangeable. In the former case it is of such an extreme association as to be confined to a very limited geographical region. Using the parasites as “biological tags” in such cases appears to have great possibilities. In specific diagnosis and in creation of new species information could be gleaned from the study of other characteristics such as ovic embryos. Biochemical and histochemical investigations such as the formation of ovic embryos offer interesting new avenues of research.
pp 190-198 October 1966
Dehydrogenase activities of tobacco K-49 in the absence of a designed supply of micro-nutrients (zero boron) were found to be reduced to 44% of the control and stepped up by the optimal boron concentration (0·75 mg./kg.) to 96 per cent. The activities were more or less equally favoured by boron concentrations from 0·75 to 1·50 mg./kg. The activities were maximum in middle leaves and minimum in old leaves; young leaves and young roots fall in between in this respect.
In the absence of micro-nutrients polyphenoloxidase activities were reduced by about 35% and with the supply of the optimal concentration of boron a recovery of 20% took place. Boron feeding increased this activity up to 0·50 mg./kg. and maintained it up to 0·75 mg./kg. Higher doses, however, up to 1·50 mg./kg. resulted in slight inhibition of this activity, with a further increase in boron up to 2·00 mg./kg., the decrease was considerable. It was noticed that polyphenoloxidase activity was low in the old leaves and high in the young leaves and young roots.
The significance of these results have been discussed.
pp 199-204 October 1966
Effect of boron-nutrition on the rate of oxygen uptake by the root-tip and shoot tip and on the ascorbic acid content in young leaves of tobacco, K-49 have been investigated.
The effect of boron-nutrition on the rate of aerobic respiration of root and shoot-organs is different. Boron up to a concentration of 0·25 mg./kg. increases respiration in the case of roots whereas in the case of shoots a consistent decrease up to a concentration of 0·50 mg./kg. is in evidence. Increase in respiration in the boron-deficient shoots is suggested to be due to high sugar content in this region and not due to the increased polyphenoloxidase activity as suggested by Mac Vicar and Burris. Participation of ascorbic acid with respiration of the boron-sufficient plants is indicated. Ascorbic acid content of the tobacco young leaves definitely increases by boron feeding. The increase is slow up to 0·75 mg./kg. but further there is a rapid increase up to 1·5 mg./kg. which accounts for about 50% increase in the vitamin content. The highest concentration of 2·00 mg./kg. tried has, however, decreased it slightly though still keeping at a higher level than the control.
pp 205-215 October 1966
Antarctica is an important component of Gondwanaland, and its geology has many points of resemblance with that of India. The high grade metamorphic rocks, of which charnockite is a conspicuous member, have many characteristics which are common to both regions. Khondalites, pink granites and gneisses, and enderbites are associated with charnockites. Regional metamorphism has often charnockitized the country rocks with formation of “phantom charnockites”, and ultrametamorphism has resulted in migmatization and rheomorphism. Palingenetic charnockites exhibit intrusive phenomena. Faulting and repeated large-scale block movements are common. Charnockites of widely differing ages have been recognized. A widespread plutonic activity took place about 500 million years ago.
pp 216-223 October 1966
The flower inCabomba caroliniana is trimerous. There are three free carpels and each encloses three ovules; of these one is attached to the midrib and the other two are laterally disposed.
The thalamus exhibits a vascular plexus from which traces to perianth, stamens and carpels are given off. The stamen is traversed by a single median bundle. Each carpel is traversed by a single bundle which trifurcates at its base forming one median which extends up to the tip without branching, and two laterals extending to the base of the style where they fuse and supply the median ovule. Among the two lower ovules one receives supply from both the median and one of the lateral bundles of the carpel and the other from only the other lateral. The tapetum is of the secretory type. Cytokinesis in the microsporocytes is of the successive type and the pollen grains are two-celled at the shedding stage.
pp 224-230 October 1966
Sugarcane variety Co. 449 is highly susceptible to strain D of the red-rot pathogen,Glomerella tucumanensis. This precludes the variety from being cultivated in northern India where the disease takes a heavy toll. Plants obtained from vegetative buds exposed to 500 r, 1000 r, 2,000 r, 3,000 r, 4,000 r, 5,000 r and 10,000 r of gamma radiation from a cobalt60 source were inoculated with the D strain. One plant each from the vegetative progeny of buds subjected to dosages of 500 r and 3,000 r were found to be resistant while all the others (an average of about 1,500 for each dosage) were susceptible. The mutant clones were morphologically indistinguishable from the original variety and possessed its other agronomic attributes also. These selections were made from individual inoculation and study of about 65,000 stalks of the sugarcane variety. Both the mutant clones arose from the third bud of the cane arising from the irradiated bud. The interesting fact that mutations almost invariably seem to appear in buds 3 to 7 of the cane arising from the mutation treated bud is believed to be the result of diplontic selection.