TRYPANOSOMES OF FISH 



GOl 



(Fig. 243, 7-8), as pointed out by Laveran and Mesnil (1901c) and Minchin 

 (1909). There are large forms (T. remahi var. magna) measuring 45 to 57 

 microns in length, of which nearly 20 microns is taken up by the flagellum, 

 and small forms {T. retnaJd var. parva), which may have a body 10 to 25 

 microns in length with a flagellum from 10 to 17 microns long. It seems 



Fig. 244. 



-Diagram of Tkypanosomes in the Blood of a Fish and in 

 THE Leech. (After Wenyon, 1922.) 



A. Trypanosomes in blood of fish. B. Developmental forms in stomach of leech. 



S. Trypanosomes in stomach of leech. P. Develoj^mental forms in proboscis sheath. 



C. Crithidia forms in proboscis sheath of leech. 



D. Metacyclic trypanosomes in proboscis sheath of leech. 



hardly probable, however, that the forms seen in the pike belong to two 

 species, though Minchin (1909) asserts that the two types are sharply 

 marked off from one another. 



Some of the larger trypanosomes of fish, as, for instance, T. perccE 

 Minchin, 1909, of the perch, may have long longitudinal myonemes w^ell 

 developed (Fig. 243, 12). 



Susceptibility of Fish. — Trypanosomes of fish are directly inoculable 

 from one to another. Thus, Laveran and Mesnil (1904) state that they 



