THE H^MOFLAGELLATES. 303 



Reptilian Forms. 



Trypanosomes have been but rarely found, so far, in Reptiles. The only 

 one described and figured is — 



T. damonitB, Lav. and Mesn., 1902. Length 32 /^, breadth 4 /x. The 

 body (fig. 16 j) is fusiform and fairly wide in the middle, but in general 

 structure presents nothing remarkable. The parasite often appears rolled 

 up on itself. The chi-omatic grains in the cytoplasm are more or less 

 uniformly distributed throughout the body, the posterior end being, if 

 anything, freer. 



In addition, Dutton and Todd (21) mention having observed Trypano- 

 somes at rare intervals in the blood of tortoises, and Gehrke ' has noticed 

 one in a gecko. 



Forms parasitic in Amphibian hosts. 



T. rotatorium (Mayer). (Synn. Amoeba rotatoria and Paramce- 

 cium costatum or loricatum, - Mayer, July, 1843; Trypanosoma 

 sanguinis, Gruby, Nov., 1843 ; Undulina ranarum, Lankester, 1871). 

 — The great variation in form exhibited by this parasite has been already 

 discussed. Two principal types are distinguished, one having the surface 

 of the body thrown into parallel ridges, which run either longitudinally or 

 with a slightly spiral course, the other having a smooth regular surface. 

 These two types and the manifold varieties of shape are best realised by a 

 comparison of figs. 17 a and B, 56. 



In size, the parasites vary from 40 — 60 M in length, by from 5 — 40 /* in 

 breadth ; the two dimensions vary more or less inversely, the width being 

 greatest when the parasites are relatively short, which gives them often an 

 extremely broad and stumpy appearance. Correspondingly, the anterior 

 end may be either drawn-out and finely pointed, in the comparatively 

 narrow forms, or conical, obtuse, or even blunt and rounded, in the stumpy 

 ones. The undulating membrane is very well developed and thrown 

 into numerous folds. The free portion of the flagellum is usually com- 

 paratively short. The kinetonucleus is generally situated some distance 

 from the non-liagellate or anterior extremity,^ and may be quite close to 

 the trophonucleus (figs. 17 b, 56 a) ; sometimes, however, it is fairly 



1 ' Deutsche med. Wochenschrift,' 1903, p. 402. 



- From the drawings given, " Amoeba rotatoria" is almost certainly a 

 Trypanosome, the other organism much more doubtfully so ; hence the 

 first-named specific designation. 



^ With regard to the bearing of this point upon the correct generic position 

 of this form see above, p. 288. 



