298 



The above table indicates that successful cultures ranging h-om 

 25 to 100 per cent, are obtained when the solid type of medium is em- 

 ployed and that in every case where the liquid medium is used negative 

 results occurred. In the successful cultures growth always resulted in 

 the water of condensation after a period of incubation from one to four 

 weeks at a temperature ranging from 25° to 28° C. 



We therefore naturally were very much interested when in 1914 

 Rh. Erdmann^ announced a new liquid culture medium for Trypanosoma 

 Brucei. Erdmann states that by using the plasma of the host as the 

 medium she grew Trypanosoma Brucei in hanging-drop cultures and 

 kept them in normal condition for an indefinite period. The technique 

 employed in brief was as follows : The plasma was obtained by the 

 method of Harrison'', Burrows', and Walton'. "The blood from the in- 

 fected rat was taken and put into a small drop of plasma on a cover- 

 glass and then this was further diluted with plasma in order to reduce 

 the number of blood corpuscles in the hanging-drop which was taken 

 from this." The cover glass with hanging-drop was either placed on a 

 depression or regular slide and sealed. Precautions to secure aseptic 

 conditions were taken. 



We attempted to follow the technique thus outlined as nearly as 

 possible. These cultures showed no signs of bacterial contamination at 

 the end of forty-five days. In only a few instances were actively motile 

 survivals in evidence for more than five days when kept at 10°C. In 

 preparations incubated at 20 °C, or above no survivals were observed 

 after forty-eight hours. 



In the course of an extensive series of attempts using heterologous 

 and homologous sera under various conditions we found it impossible at 

 any time to obtain a second generation by the Erdmann method. The 

 homologous sera used were rat and guinea pig. The heterologous sera 

 were human, horse, beef, sheep, pig, rabbit and chicken. These sera 

 were used in a dilute one to one, inactivated, and normal form and the 

 preparations were incubated at temperatures of 10, 15, 20, 25, 28, 30, 

 35, Pj1V2, and 40 °C. Ascitic fluid was also used without success. 



It is true that trypanosomes will multiply and remain actively 



■> Soc. Exp. Biol, and Med., 1914, XII, p. .57. 



'' Proc. Soc. Exp. Biol, and Med., 1907, IV, p. 10: Jour. Exp. Zool., 1010, IX, p. 787. 



"Jour. Amer. Med. Assn., 1910, LV ; Jour. Exp. Zool., 1911, X, p. 63. 



^ Proc. R. S. L., Ser. B., 87, p. 452. 



