Scientific Proceedings. 



(90 V 



means of differentiating them into species. A study of the twenty- 

 five cultures obtained showed that they represented three, if not 

 four, and possibly more distinct species. The cultural character- 

 istics were extremely well marked, and offered an admirable means 

 of differentiation. One species, more common than any of the 

 others, was specially mentioned at this point. Its cultures present 

 an extremely interesting appearance and are unusually luxuriant. 

 They show two types of cells. One of these is round or in short 

 spindles, which always occur in rosettes, with the flagella directed 

 centrally, as in the case of Trypanosoma lewisi. The other type 

 is long and very slender, almost a mere line, and is extremely 

 motile, traveling forward and backward, with great rapidity. Very 

 often two cells unite by their posterior ends ; at times agglutina- 

 tions are found and in these the whips are found situated on the 

 outside of the mass. This long, slender type corresponds exactly 

 to the Spirochete described by Schaudinn, while the other type 

 agrees with his Trypanosoma. 



It is noteworthy that inoculation of the trypanosome cultures, 

 even in large amounts, into birds failed to produce any cytozoa. 

 In one case a canary infected with such a culture showed trypano- 

 somes in its blood for three months without any sign of an 

 intracellular parasite. 



These facts are of importance, because of their bearing on the 

 recent views of Schaudinn regarding the relation of trypanosomes 

 to the intracellular parasites. As is well known, this distinguished 

 protozoologist believes that in the case of Jialtcridium the sexual 

 forms unite in the stomach of the mosquito to form ookinetes, 

 which then develop into indifferent, male and female trypano- 

 somes. This type agglutinates with the flagella directed toward 

 the center. In the case of H. ziemanni, he holds that a similar 

 change occurs in the mosquito, giving rise to long, slender spiro- 

 chetes, which agglutinate with the flagella directed outward. 

 Injections of suspensions of such infected mosquitoes produced 

 the characteristic infection with the hemocytozoa. 



It will be seen that the results obtained by the authors do not 

 bear out Schaudinn's conclusion. The authors have shown that 

 birds may harbor trypanosomes, even for months, without show- 

 ing any intracellular parasites. On the other hand, birds rich in 



