214 H. M. WOODCOCK. 



lewisi (16 a), T. remaki (17 l), and T. raj^e (62 b), or in 

 the non-flagellate half, as in T. damouise (16 j) and in 

 T. nelspruitense (17e); in Trypanoplasma borreli it 

 is often comparatively far forwards (fig. 18). In some cases, 

 at all events, the position is by no means constant (cf. T. 

 equinum [figs. 16 d, 47] and T. evansi [figs. 42 a, 45]). 

 The trophonucleus presents no striking variations in size, 

 which, indeed, appears to be often independent of the size 

 and shape of the parasite. Thus in T. rotatorium it is 

 scarcely larger than that of many slender Mammalian or 

 Piscine forms, in which it occupies almost the entii'e breadth 

 of the body. The trophonucleus attains, perhaps, its greatest 

 size in the large T. theileri and T. rajge. In form it is 

 generally ovoid, the longer axis being directed longitudinally, 

 but in the Trypanosome described by Dutton and Todd from 

 Senegambian birds, and, similarly, in Hanna's Trypanosome, 

 the long axis is transverse to that of the body (figs. 52, 53). 

 The shape of the trophonucleus in the latter instance is also 

 unusual, resembling an isosceles triangle. The minute struc- 

 ture is generally described as consisting of a more or less 

 compact aggregation of chromatin grains embedded in a 

 plastin-like base or matrix; these may be uniformly dis- 

 tributed throughout the nucleus, or more closely packed in 

 the peripheral part, leaving a clearer central area (tigs. 19, 

 44, 56). No mention is usually made of a nuclear membrane 

 or distinct nticulum.' In T. remaki, possibly also in T. 

 ^olege, and in Trypanophis, there is a large, deeply- 

 staining granule in the centre of the nucleus, surrounded 

 by a clear area, which ])robably represents the troplio- 

 nuclear centrosonie (karyocentrosome) ; in Tr3'panophis 

 this granule appears to divide by simple mitosis (fig. 

 41). 



Of the highest importance is Schaudinn's revelation of the 

 true nature of that hitherto enigmatical and much-discussed 

 chromatic body, which is situated near the root of the 



' Prowazek describes a nuclear reticulum in both T. lewisi and T. 

 bi'ucii. 



