Volume 3, Issue 2
February 1936, pages 107-174
pp 107-114 February 1936
Clinical, epidermiological or experimental facts do not authorise the conclusion that urinary Bilharziosis may become endemic in Portuguese India.
However, one definite autochthonous case of human urinary Bilharziosis has been registered in the village of Valpoy where from 1912 to 1934 were living African troops infected with these trematodes.
Unless some other mechanism of infection be discovered, it is reasonable to believe that some local mollusc has conveyed the infection.
This intermediary mollusc cannot be anhabitual host—as the epidemiological facts are entirely against such an hypothesis—but a snail in which this infection occurs rarely and in some wayaccidentally.
On this point of view we propose the division of the vectors of Schistosomiasis into 3 groups:habitual, secondary andeventual, according to the evolutive cycle occursin natura and frequently,in natura or experimentally but rarely and at last, aseventual those who having shown a definite miracidial attraction, often followed by penetration, have not, under experimental conditions, demonstrated the final phase of sporocyst or cercaria.
We believe that sucheventual hosts are responsible for the sporadic cases of Bilharziosis occurring in an indemn area, after the import of this disease from abroad.
Among such molluses two species are found in Valpoi:Melanoides tuberculatus already incriminated by Gopsill, andLimnœa luteola Lamarckf. pinguis Dohrn, where an evident miracidial attraction often followed by penetration was definitely seen.
pp 115-119 February 1936
pp 120-124 February 1936
pp 125-127 February 1936
pp 128-142 February 1936
pp 143-150 February 1936
During decomposition of glucose by the mixed flora of the soil, a considerable part (over two-thirds) of the sugar is converted into gaseous forms in the course of the first four days. The residue is present in water-soluble forms, chiefly as organic acids. The latter are largely utilised for the fixation of nitrogen.
The water-soluble products left after the decomposition of surgar, if inoculated with the mixed flora of the soil, can fix nearly two-thirds as much nitrogen as the original surgar itself. The solid sediment (including the major part of the organism), when left by itself, does not fix any appreciable quantity of nitrogen.
pp 151-156 February 1936
The rôle of lime in the fixation of atmospheric nitrogen by the mixed flora of the soil has been studied.
It has been found that consequent on the decomposition of sugar, there is much production of acid that neither a dilute solution of buffer nor periodical addition of alkali helps to maintain the medium at the optimum reaction. In presence of excess calcium carbonate, the acids are neutralised as fast as they are produced with the result that the medium continues to remain neutral and the fixation proceeds unimpaired.
Strontium carbonate can replace the calcium salt in the nitrogen fixing medium. Barium or magnesium carbonate is not so useful. Addition of minute quantities of calcium sulphate helps to improve the fixation.
pp 157-164 February 1936
It must be remembered, however, that practically all this palæontological evidence in support of an eocene age for the Deccan trap comes from plant fossils; and the question naturally arises as to what dependence is to be placed upon fossil plants as a guide to geological age—how far they could be considered “absolute indicators of a geological horizon”. Whenever there has been a possible difference of opinion on the age of a bed as determined by the evidence of terrestrial fossil plants as against fossil marine animals, it is true that the geologist will always prefer the evidence of the latter and fix the age accordingly. But in a case like the age of the inter-traps where the decisive evidence of fossil marine animals is not available, it seems only reasonable to accept an age based on the verdict of the plant fossils, unless such a conclusion can be shown to be definitely unacceptable from the geological side.
pp 165-174 February 1936