THE H2EM0FLAGELLATES. 207 



same species ; as Laveran and Mesnil point out, it is pai"- 

 ticularly plastic. Hence, in the following examples, it must 

 not be inferred that the parasites always conform to that 

 particular description, but merely that such and such a mode 

 of termination is usually to be noted in their case. The non- 

 flagellate end may be much drawn out and pointed, as in 

 T. lewisi, T. ziemanni, T. avium, and T. inopinatum; 

 or shorter, and sharply acute, as in T. gambiense, T. granu- 

 les um, T. equinum (fig. 16 d). In other instances it may 

 be obtuse or even rounded off at the tip, as in individuals of 

 T. brucii (fig. 42 b), T. equiperdum (fig. 42 c), and, some- 

 times to a marked degree, in T. dimorphon (fig. 49 i) ; 

 although these are all relatively slender forms. Nor does it 

 always follow that the non-flagellate end is blunt in the thick, 

 fusiform parasites; it tapers very finely in T. paddse (fig. 

 54), and in Hanna's Trypanosome it is extremely long and 

 attenuated (fig. 10 g). Lastly, figs. 17 a and b, 56 show the 

 different modifications in this respect in T. rotatorium. In 

 one or two instances, the extreme tip evinces a certain degree 

 of contractility,^ as seen in fig. 42 d of T. equiperdum, 

 where it is retracted, so that the extremity appears forked or 

 bifid. Dutton and Todd seem to have observed a similar 

 appeara;nce in the case of T. rotatorium. 



The flagellate end of the body is more uniform and nearly 

 always tapering; it sometimes thins away so gradually (e.g. 

 fig. 16 f) that it is difiicult to be quite certain of the exact 

 point where it passes into the flagellum. In one or tAvo cases, 

 however, it ends rather abruptly (e. g. T. solese, fig. 17 j). 



There are two flagelia only in T ry p an o plasma and 

 Trypanophis. They are inserted into the body very close 

 to the anterior end, just to one side of the rostrum. The two 

 flagelia are quite separate from each other, and, while one 

 (that most anteriorly situated) is entirely free and directed 

 forwards, the other at once bends backwards and is attached 

 to the convex (dorsal) side of the body, throughout the 

 greater part or all the length of the latter. Posteriorly this 



' Compare the active, sensitive, beak of Try pan opl as ma borreli. 



