306 H, M. WOODCOCK. 



anterior extremity. A noticeable feature is the presence of a chain of 

 chromatic rodlets (perhaps really a chromatic thread) running from one 

 nuclear body to the other. The loops of the undulating membrane are not 

 so wide as in T. mega. 



T. inopinatum, Sergent, 1904. Length 25-30 /i ; breadth 3^. The shape 

 of this parasite is that of a typical Mammalian or Piscine Trypanosome 

 (fig. 17 c). It is very like T. remaki, being slightly wider than T. lewisi, 

 which, however, it more resembles in having the anterior end finely taper- 

 ing. The kinetonucleus is well developed, and often stretches transversely 

 across the body, in a rod-like manner. It is usually situated about midway 

 between the trophonucleus and the anterior extremity, but may be nearer 

 either the former or the latter. (V) host, liana esculenta; (I) host, a 

 leech, Helobdella algira. Billet's very important work on the alter- 

 nation of hosts of T. inopinatum and the parasite's relation to a Lankes- 

 terella is discussed above (p. 251). 



T. nelspruitense, Laveran, 1904. This is another very distinct and well 

 characterised form. Average length from 55 — 60 ju; breadth 3/*. The 

 free flagellum is extremely long, about 25 fi or more, or almost as long as 

 the body itself. The body is slender and vermiform in shape. The posterior 

 and is relatively short and blunt. The trophonucleus lies well in the 

 anterior half. The cytoplasm in the hinder two thirds of the body is dense 

 and uniformly filled with deeply-staining grains ; that in the anterior third 

 is much clearer and faintly-staining, with only a few small grains, and 

 around the nucleus itself there is usually a quite pale zone. This Trypano- 

 some somewhat resembles T. granulosum of fishes. The name of the 

 frog in which the parasite was found is not given. 



Forms Parasitic in Piscine Hosts. 



These Trypanosomes are, on the whole, very uniform in shape, being 

 typically fusiform and slender. The alternate, Invertebrate host is most 

 probably, in all cases, a leech. This has already been proved by Lcger (66) 

 for T. barbatulse (also for a Trypanoplasma, see above, p. 250); 

 moreover, various workers have remarked on the general occurrence of 

 Ichthyobdellids (Ilemibdella, Piscicola, Pontobdella) on the skin 

 of infected fish (vide e.g. L. and M. [51]). 



T. remaki, Lav. and Mesn., 1901. This parasite occupies a correspond- 

 ing position among Piscine forms to that of T. lewisi among Mammalian 

 Trypanosomes. It is very slender, with tapering, pointed extremities, not 

 quite so drawn-out, however, as in T. lewisi. The trophonucleus is in the 

 posterior half of the body, and often shows a large, deeply-staining grain 

 centrally (ceutrosome?). Laveran and Mesnil distinguish two varieties, 



