Volume 10, Issue 1
July 1939, pages 1-109
pp 1-26 July 1939
pp 27-40 July 1939
A detailed study has been made to elucidate the after-effects of the addition of certain fertilisers,e.g., ammonium sulphate, ammonium phosphate, potassium sulphate, superphosphate and potash mixture on the growth and water requirement of wheat.
Treated plants in general exhibit decided improvement in their growth than the untreated ones. While the height, tiller number and total dry matter accumulation per plant are significantly better in all the fertilised series than the unmanured ones, K78.7 (potassium sulphate) and P66 (superphosphate) applied alone do not show significantly higher increase in the yield of grain and straw as also of the length of earhead or the absolute weight of the grains.
The general effect of the fertilisers is to cut short the water requirement of the treated plants to values much below that obtained for the control ones although with P66 (superphosphate) and N16.5K18P16.5 (potash mixture) the differences are not statistically very significant. The total amount of water necessary for raising a successful crop of wheat is therefore less in certain cases,e.g., potash sulphate and superphosphate, while in other series it increases beyond the values recorded for control apparently due to the very high yield of grain obtained in these cases. Thus, the application of fertilisers besides showing the higher yield of the crop has the added advantage of minimising the cost of irrigation.
pp 41-80 July 1939
pp 81-87 July 1939
The presence in the latex, and more especially in the pulp of the papaya fruit, of a system responsible for maintaining the thiol compounds in the reduced condition is clearly established. Its thermolabile character is indicated by the observation that a preliminary heating of the latex dispersed in buffer or the press-juice from the pulp to a temperature of 50°C. for a period of 60 minutes, renders it inactive. The system present in the papaya, in these respects, is analogous to that in the liver described by Hopkins. Further work is called for in order to determine the exact nature of the mechanism.
The significance of this finding lies in the fact that the reducing system provides a regulating mechanism for the proteolytic processes in the plant, the concentration of the SH compounds which function as the natural activators of papain being conditioned by the activity of this system. It also helps, indirectly, to maintain the ascorbic acid present in papaya in the reduced condition, as the thiol compounds afford complete protection to the vitamin against oxidation by hexoxidase or copper as previously shown by Hopkins, and confirmed by us.
pp 88-97 July 1939
Marchantia palmata which grows commonly at Ootacamund on the Nilgiris forms plenty of androgynous receptacles.
These receptacles start as purely female receptacles, but soon one or more proliferations bearing antheridia grow out from its under surface.
These proliferations are merely the archegonia-bearing lobes of the female receptacle which become active again and continue to grow further into narrow elongated outgrowths.
The proliferations produce at first sexual structures which are intermediate between an archegonium and an antheridium and later on typical antheridia. A consideration of these intermediate structures suggests that antheridia and archegonia are homologous structures.
A fungus forming pycnidia is generally present in the liverwort. It could not be dicided whether the change of sex in the receptacle is due to this fungal attack.
pp 98-109 July 1939