74 SUMMAEY OF CURKENT RESEARCHES RELATING TO 



mena, and does not con'espond to sex-differentiation. The shorter 

 forms are those destined to carry on the cycle in the transmitting host. 

 The blood is not infective to fly {a) just before an outburst of multipli- 

 tion ; (h) during the destruction of trypanosomes preceding a depressed 

 period ; (c) at the summit of an exalted period involving very numerous 

 trypanosomes, when the parasites often show signs of exhaustion ; and 

 (d) during certain periods of rapid multiplication when both the absolute 

 and relative numbers of the shorter forms are low. 



Agglutination of Treponema drosophilae.* — E. Chatton describes 

 this new species from the intestine of Drosophila, and calls attention to 

 the fact that the cell-sap of the intestinal cells of the insect host brings 

 about the phenomenon of agglutination. That is to say, the cytoplasm 

 of the parasites becomes more viscous and quite homogeneous, and an 

 aggregation in bundles takes place. In the cavity of the gut, when the 

 intestinal cells are intact, there is no such phenomenon. The ordinary 

 digestive juices have no effect. 



New Blood-parasite of Pigeon.t — A. Carini describes from the 

 red blood corpuscles of the pigeon a refringent corpuscle, which seems 

 to be a Hsematozoon related to Hsemoprotens and Plasmodium. He 

 names it provisionally Plasmodium columbse sp. n. It grows from a 

 minute spherule into an oval, which becomes slightly dumbbell-like, 

 and may give off pseudopodia within the blood- corpuscle. 



* O.B. Soc. Biol. Paris, Ixxiii. (1912) pp. 212-14. 

 t C.R. Soc. Biol. Paris, Ixxiii. (1912) pp. 396-8. 



