426 SUMMARY OF CURRENT RESEARCHES RELATING TO 



indication that the parasite produces malarial or febrile symptoms, and 

 the author is disposed to regard Trypanosoma as a commensal rather 

 than a parasite. Dead parasites, in addition to living ones, occur in the 

 blood, and the author regards the Amoeba rotatoria of Mayer as a mori- 

 bund form of Trypanosoma, though its position in the life-history has 

 yet to be determined. 



La Tristeza.* — Under this name is known in the Argentine and 

 Uruguay the disease called elsewhere Texas and Tick fever. In refer- 

 ence thereto, J. Lignieres confirms the observations of Smith and 

 Kilborne on Piroplasma bigeminum, and adds some further information 

 on the evolution of the parasite, its artificial cultivation, and on vacci- 

 nation against La Tristeza. 



The transformations of the parasite were followed out in the stomach 

 of the tick, and also in cultures made in defibrinated blood and incubated 

 at laboratory temperature. 



* Ann. Inst. Pasteur, xv. (1901) pp. 121-8 (1 pi.). 



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