Volume 57, Issue 5
May 1963, pages 275-338
pp 275-289 May 1963
pp 290-296 May 1963
On cold acclimation, mussels show a decrease in the blood chloride and free amino-acids, while blood calcium increases. A slight increase in blood sodium and potassium is also noticeable. Cold-acclimated earthworms also show similar changes except that the increase in Na and K is more conspicuous than in the mussel. In addition to this, magnesium in the body fluids also decreases. These changes are discussed and it is suggested that the ionic changes influence muscle activity and metabolism while the decrease in the amino-acids might be a result of increased degree of protein synthesis.
pp 297-299 May 1963
Physiology of low temperature acclimation in tropical poikilotherms - II. Interferometric analysis of the protein content of blood cells in the freshwater mussel,Lamellidens marginalis, and the earthworm,Lampito mauritii
The protein content in the cells increases on cold acclimation, the increase being 21·5% in the mussel (Lamellidens marginalis) and 31% in the earthworm (Lampito mauritii).
pp 300-306 May 1963
The paper deals with the morphological studies of a North Indian species ofMeringium, M. edentulum (v.d.B) Copel. collected from Khasi and Jayantia hills of Assam.
The numerous roots, coming out irregularly from the rhizome and densely covered by unicellular hairs, are usually diarch, rarely triarch also. The rhizome is black in colour, creeping and has a mesarch protostele. The leaves are once pinnate with a free dichotomous venation. Dermal appendages are one to three celled hairs and are present only on the rhizome and not on the leaf.
The sorus is terminal on the lowest pinnules of the upper pinnae. The indusium is cup-shaped in its lower half and is bivalved in the upper half. The receptacle is included at first but becomes excluded later on.
pp 307-325 May 1963
pp 326-338 May 1963
Essentiality of thiamine for the growth and sclerotial formation ofSclerotium rolfsii was confirmed. It was found that concentrations of thiamine ranging from 0·10 µg./flask up to 25·0 µg./flask were equally good for growth and sclerotial production. The presence of interaction among the several vitamins added was shown. Hexose sugars were found to be the best sources of carbon and the inability of the fungus to form sclerotia in organic nitrogen sources was discussed. It was shown that the fungus can grow in a wide carbon/nitrogen ratio and that it was the absolute amounts of carbon and nitrogen that mattered. The pH range for both growth and sclerotial production was observed. In all the treatments where good growth was obtained, regardless of the initial reaction the final pH was near 4·0. The requirements for sclerotial production were shown to be not similar to those suitable for growth. The significance of such a phenomenon in a vegetative type of reproduction like sclerotial formation is discussed.