690 II. M. WOODCOCK. 



scanty in the blood. 'J^he p;irasites are numerous, nearly all 

 being, of course, in one or tlie otlier variety of the trypano- 

 tnonad phase. Exceptionally, however, individuals occur 

 which show the trypaniform condition; for example, on a 

 smear containing between two and three hundred parasites 

 there are four or five such, three of which are drawn in 

 figs. 129-131. I have not found any which correspond 

 exactly to the individuals of this type just described. The 

 pai'asite in fig. 129 approximates faii'ly closely to those of 

 figs. 126 and 127, but it is distinctly shorter and relatively 

 not quite so slender. The two other individuals, on the other 

 hand, while altogether much larger, are still vei-y slender in 

 proportion to their length ; and in these the aflagellar part is 

 veiy prolonged and vermiform. While agreeing in general 

 form and character with the parasite, for instance, of fig. 10, 

 they represent, it would seem, an older, later condition. The 

 individual of fig. 180 has attained, probably, the fullest deve- 

 lopment of this type, at least as far as the culture is concerned ; 

 it constitutes, I consider, a most important phase. 



The length of the body alone is 36 fi, and its greatest 

 width 2 fx ; the distance of the kinetonucleus from the 

 aflagellar extremity is H-r f^- The free flagellum is only 8/u 

 long. The trophonucleus of this individual presents a 

 remarkable appearance (fig. 130). The chromatin is arranged 

 in a series of short transverse bars, forming a longitudinal 

 row — hence the description "ladder-like." I have found a 

 quite similar condition in two other examples of this type ; 

 but in the other large vermiform individual I have figured 

 (fig. 131) the chromatin is not arranged in such a definite ladder- 

 like manner, but appears to form a faii'ly regular double row 

 of grains. 



None of the trypaniform parasites which I have found — in 

 either case — showed any indications of division. 



The types above described include all the cultural forms of 

 the trypanosome observed, which I have no hesitation in 

 regarding as perfectly normal and regular. As I shall 

 mention more particularly later, they are closely paralleled 



