Volume 47, Issue 3
March 1958, pages 115-187
pp 115-123 March 1958
The chromatographic distribution of free amino acids in roots, shoots and leaves of susceptible and resistant varieties of cotton (K 2, CO 2 and MUI) at the two age-levels 6 and 12 days in healthy and diseased states is reported. The healthy resistant varieties consistently showed the presence of cystine which was absent in the susceptible ones. It is suggested that this amino acid might be related to the mechanism of wilt resistance in cotton. The apperance of cystine in diseased susceptible plants at the earlier agelevel and its disappearance with the progress of wilt is attributed to host defence reactions. The possibility of a systemic immunological response at early stages of fungal infections is suggested.
pp 124-130 March 1958
1. A pictographic summary of the variations observed during spore germination, differences in the activity of the spores during pair-wise conjugation and the mode of budding by the spore zygotes is presented.
2. Rarely the spores are capable of direct germination. When all the four spores in an ascus are germinating directly their development is not synchronous.
3. Spores germinating directly become indistinguishable from vegetative cells when they start proliferation and hence cannot be confused with waisted spore zygotes, retaining their characteristic shape even after producing a few buds, during investigations on the structure of the nucleus in living zygotes.
pp 131-139 March 1958
(1) Various formate precursors studied, aid in the conversion of glycine to serinein vitro by rat liver enzymes to different degrees.
(2) The participation of CF in the system has been demonstrated fromin vitro studies on glycine conversion to serine anaerobically and in the absence of added formate or its precursors.
(3) In a dietary deficiency of niacin, there is impairment in the activity of the glycine to serine synthesizing enzyme.
pp 140-154 March 1958
Rice plants have been grown under water culture to study the growth yield and uptake of nutrients with graded doses of 0, 5, 10, 20, 40, 60, 100, 150 and 200 p.p.m. nitrogen.
Maximum grain yield was obtained at 40 p.p.m. and at higher levels of nitrogen, the growth was considerably retarded due to nitrogen excess in the plant, thereby depressing the grain yield.
Four distinct stages of nitrogen utilisation have been observed: (i) the deficiency stage from 0–10 p.p.m. where grain yield and nitrogen content in grain both increase with increase in nitrogen supply, (ii) the normal stage from 20–40 p.p.m. where the grain yield increases with increase in nitrogen level but increase in nitrogen content of grain is not as sharp. The optimum nitrogen level lies in the range of 30–40 p.p.m., (iii) the luxury stage from 40–60 p.p.m. when the nitrogen content increases with increasing supply of nitrogen whereas there is practically no difference in the yield of grain or straw, (iv) the excess stage from 60–200 p.p.m. where the growth of crop is considerably retarded and yield decreases with increase in nitrogen supply, though nitrogen content of both grain and straw continues to rise.
Results obtained give an idea regarding optimum levels of nitrogen. 30–40 p.p.m. (corresponding to roughly 30–40 kg./ha. under field conditions) is considered optimum forindica varieties. Higher nitrogen levels are shown to result in malnutrition giving low yield of grain.
The authors are indebted to Dr. K. Ramiah, Rice Expert of F.A.O., Bangkok, for suggestion and improvement in the text of the paper.
pp 155-162 March 1958
The erythrocyte counts, hæmoglobin content, coagulation period and cell and nuclei size of the blood of Hilsa from the river Hooghly have been determined. Using the Climbing Perch as test material, it has been shown that the characteristics of the blood taken from the heart of live fish are not significantly different from those of dead fish which have been preserved in ice immediately after capture.
The mean erythrocyte count of Hilsa is much higher than that of many other species of fish and this appears to be correlated with the relatively small size of the cells. The coefficients of variation of the different characters are below 20%, which may be considered as the normal variation in the Hilsa of the Hooghly for purposes of comparison with blood samples of other stocks of Hilsa.
pp 163-172 March 1958
The structure of the thallus, formation of the spermatangia and the carpogonial branches together with post-fertilisation stages inPseudogloiophlœa fascicularis (Boergs.) comb. nov., are described in detail.
In the general features of reproduction the alga agrees withPseudogloiophlœa capensis (Setch.) Lev. described by Svedelius. The post-fertilisation stages ofPseudogloiophlœa fascicularis (Boergs.) comb. nov. appear to be similar to those ofScinaia furcellata as described by Svedelius.
pp 173-187 March 1958
The authors have described in detail the anatomy and histology of the alimentary canal of the spiny eelMastacembelus armatus (Lacép). Amongst the more important features discovered by them might be mentioned the participation of the upper jaw in the formation of the trilobed snout, which bears a cartilaginous axis in its median lobe; the presence of both maxillary and mandibular valves in the bucco-pharynx and the absence of mucous cells on them; the occurrence of taste-buds not only in the wall of the buccopharynx and on the tongue but also in the œsophagus; the disposition of the gastric glands in the stomach and the non-differentiation of their cells into oxyntic and peptic; the close histological similarity between the intestine, intestinal cæcæ and the presence in abundance of mucous cells near the anus.