606 



FAMILY: TRYPANOSOMID^ 



As regards marine fish, Brumpt (1906) studied the development of 

 T. cotti and T . solce in Trachelobdella punctata. As was subsequently con- 

 firmed by Robertson (1909) in the case of T. rajce, the trypanosomes lose 

 their fiagella, and active multiplication in the non-flagellate condition 

 takes place. It is only after some days that crithidia and trypanosome 

 forms reappear. The development is confined to the stomach. In the 

 case of T. scyllii and T. rajce, the same type of development occurs in 



^O 



Fig. 248. — The Trypanosome of the G-oldfish in Culture ( x ca. 2,000). 

 (After Thomson, J. D., 1908.) 



1-2. Forms from the blood of the fish. 3-5. Crithidia forms in early cultures. 



6. Granular crithidia forms in older cultures. 

 7-8. Crithidia form and metacyclic trypanosome form from culture on the forty-thiid day. 



Pontohdella muricata, but infection of the intestine follows the stomach 

 phase, whereupon the forms in the stomach disappear. In no case did 

 Brumpt observe infection of the proboscis sheath. In one instance, 

 T. cotti was transmitted to a fish (Cottus hubalis) by the bite of an infected 

 leech. 



Culture. — The trypanosomes of fish are easily cultivated in blood-agar 

 media. Thomson, J. D. (1908), cultivated the form in the goldfish, and 



