Volume 46, Issue 4
October 1957, pages 229-292
pp 229-235 October 1957
Synthesis of serine from ethanolamine by carbon dioxide fixation is demonstrated to take place in presence of rat liver enzymes. The system is biotin-dependent.
Serine deaminase activity but not that of serine decarboxylase is also reduced in biotin deficiency.
pp 236-240 October 1957
Aminopterin inhibits serine decarboxylation in rat liver homogenates.
Dietary deficiency of folic acid in rats also reduces serine decarboxylase activity.
Folic acid does not influence serine deamination, but glycine to serine synthesis is impaired in a dietary deficiency of the vitamin.
In folic acid deficiency liver and blood levels of choline are also lowered.
pp 241-246 October 1957
1.Hymenia recurvalis F. was found to be attacked by three primary parasites namely (1)Apanteles new species, (2) an unidentified Ichneumonid and (3) an unidentified Braconid.
2. The degree of parasitism was observed to be about 62% in case ofApanteles sp. and not significant in the two other species.
3. In spite of the two observations cited above, the pest was found to be abundant in the field throughout the period under observation and the population ofApantales sp. also remained more or less constant.
4. Investigations into the failure of the natural control by parasites to check the host population revealed the presence of eight different species of hyperparasites attacking the pupæ ofApanteles sp. and constituted a major factor in the maintenance of balance between the host and the parasites.
5. There is a wide field for research in this direction which will attract some of the younger and energetic entomologists of our country.
pp 247-253 October 1957
pp 254-273 October 1957
1. Some essential morphological and histological features of the very early and nearly mature testes inChanos are described.
2. Similar accounts of four important stages in the maturation of the ovary and the intraovarian eggs are given.
3. A study of the ova diameter measurements in the limited material indicates that the fish normally spawns only once a year. The type of spawning in the species, egg production, size at maturity and breeding habits are discussed in the light of these observations. The probable lines on which further data may be usefully gathered are also briefly indicated.
pp 274-284 October 1957
Phyllosticta cycadina, P. artocarpina andPestalotia mangiferœ were isolated from the leaf spot diseases ofCycas revoluta, Artocarpus heterophyllus andMangifera indica respectively. A detailed study of the assimilation of sucrose, maltose and lactose by these organisms was undertaken. Sucrose and maltose were assimilated through a hydrolytic pathway.Pestalotia mangiferœ utilized both glucose and fructose simultaneously, but the two species ofPhyllosticta behaved differently and consumed glucose three days before the other hydrolytic product of sucrose (viz., fructose). Synthesis of an oligosaccharide (maltotriose) was recorded during the assimilation of maltose. Lactose was used through a non-hydrolytic pathway and was found to be a poor source but a mixture of its hydrolytic products supported good growth.
pp 285-292 October 1957