124 



examination proved to be a collection of ova with, tlie head of a 

 young larva protruding from each. The mosquito, on being placed in 

 a bottle containing some water, immediately flew down to the water 

 and methodically dipped its hind leg into it, whereupon the larvae all 

 emerged and swam away. It is supposed this act of oviposition on 

 its own leg is a device by which the mosquito is enabled to lay its eggs 

 in water which is ordinarily inaccessible to it, or it may be a means of 

 saving the eggs from some danger which they might incur if laid directly 

 on water, 



CoENWALL (J. W.) & Menon (T. K). A Contribution to the Study of 



Kala-azar (III). — Indian Jl. Med. Research, Calcutta, iv, no. 4, 

 April 1917, pp. 672-687. [Eeceived 26th June 1917.] 



Two classes of flagellates occur in nature, one that flourishes in the 

 presence of bacteria, and another that rapidly dies in their presence. 

 There are also two classes of insects, those whose alimentary canal 

 contains numerous bacteria obtained from a diet of non-sterile 

 substances either throughout life or only in the larval stage, as is the 

 case in the cockroach or house-fly and mosquito respectively, and 

 insects whose alimentary canal is sterile owing to their having lived 

 on sterile food, such as blood obtained through a long, puncturing 

 proboscis. Hence, assuming that the flagellate stage of Leishmania 

 donovani and L. tropica cannot occur in the stomach of an insect in 

 which bacteria abound, the number of hosts is limited. The multiplica- 

 tion of flagellates of Leishmania in the stomach of bed-bugs {Cimex) 

 is seldom very profuse and sometimes scarcely occurs at all ; on rare 

 occasions only, living flagellates of L. donovani have been found in 

 the intestine and rectum of artificially infected bugs. There is a very 

 considerable weight of evidence against the transmission of both 

 typhus and spirochaetes by bugs in the act of feeding and a less 

 amount against the transmission of plague. They may however 

 occasionally infect healthy animals either by regurgitation or by 

 washing out with their saliva infective material which has remained 

 in the lumen of their sucking tubes, though attempts to induce re- 

 gurgitation of flagellates of L. donovani by infected bugs have had 

 negative results. The flagellates of both L. donovani and L. tropica 

 grow well in a medium prepared from the blood of the monkey, Macacns 

 sinicus, and the former have been cultivated from the peripheral 

 blood in cases of kala-azar even during ap3rrexial periods. 



Sen (S. K.). A preliminary Note on the R61e of Blood in Ovulation in 

 Gulicidae. — Indian Jl. Med. Research, Calcutta, iv, no. 4, April 

 1917, pp. 729-753. [Received 26th June 1917.] 



The view that mosquitos require meals of blood to propagate their 

 species has been so widely held, without experimental proof, that 

 attention has recently been drawn to the facts that mosquitos occur in 

 uninhabited regions in Greenland ; that they occur in large numbers 

 in tracts in which there is no epidemic malaria ; that large numbers 

 of mosquitos live with very few chances of getting blood ; that 

 substances, other than blood, have been found in the alimentary tract 

 of females that have laid eggs in captivity ; and that they have been 



