THE HiEMOPLAGELLATES. 307 



characterised by difference in size.' They consider the morphological agree- 

 ment between the two kinds of form to be, otherwise, too close for them to 

 be assigned to different species, especially since both occnr in the same host, 

 namely, Esox lucius, pike. T. remaki, var. parva (fig. 59). Length 

 (medium) about 30)tt, of free flagellum alone 10 — 12 ;« ; breadth Ih/x. Cer- 

 tain individuals may, however, reach a length of 42 /i. The cytoplasm is 

 fairly homogeneous and faintly-staining. T. remaki, var. magna (fig. 17l). 

 Minimum length 45 /«, of which 17 — 20 )« is for the flagellum ; breadth 2 — 

 2| /«. In tlie largest forms the length may attain 57 /». Tlie cytoplasm 

 appears more deeply-staining than in the other variety, but, as Laveran and 

 Mesnil point out, this may be partly due to the increased thickness. 



Fig. 59. Fig. 60. 



B. 



Fig. 59. — T. remaki, var. parva. Lav. and Mesn. X 2000. 

 (After L. and M.) 



Fig. 60.— A, T. danilewskyi; b, T. tincse. X 1500. (After 

 L. and M.) 



We have, next, a series of forms, from closely allied hosts, many of which 

 are, doubtless, the same as those noticed by earlier observers, e. g. Chalach- 

 nikow and Danilewsky, but which, for the most part, have been left for 

 Laveran and Mesnil and Lcger to rediscover and name. 



T. danilewskyi. Lav. and Mesn., 1904. Length 35 — 45 /* by about 3 fi 

 in width. Free portion of flagellum 15 — 17 ft. The anterior end (fig. 60 a) 

 is shorter and more bluntly conical than in T. remaki. The undulating 

 membrane is rather better developed, with wider folds. The nucleus is 

 rather nearer the posterior than the anterior end. (V.) host, Cyprinns 

 carpio, carp (probably also in the minnow [Phoxinus], Laveran [39 a]). 



' Laveran and Mesnil say they have not noticed any stages which might 

 be regarded as intermediate between the two varieties. Nevertheless, as is 

 apparent from the dimensions given, the maximum size of the smaller 

 variety closely approaches tlie minimum of the larger one ! 



