480 



Col. Sir D. Bruce and others. 



[Aug. 3, 



From this curve it will be seen that T. simice is a rnonomorphic species, 

 varying from 14 to 24 microns in length, the greatest number of individuals 

 (25 - 2 per cent.) being 18 microns long. 



Breadth. — Measured across the broadest part T. simice averages 1'75 microns 

 in breadth (maximum 2"75, minimum 1). 



Shape. — These trypanosom.es are rnonomorphic and, as a rule, fairly 

 uniform in shape. The body is elongated, markedly undulating, and 

 frequently extends in a straight line (Plate 13, fig. 2). The posterior 

 extremity is bluntly pointed or rounded, and there is frequently the appear- 

 ance of a vacuole at the extreme end, as shown in figs. 6, 9, 11, 16, 17, and 

 18. The anterior extremity is pointed. 



Contents of Cell. — Clear, homogeneous, and free from granules. 



Nucleus. — Oval, and situated about the middle of the body. 



Micronucleus. — Small and round, situated almost invariably about 

 1| microns from the posterior extremity. A peculiarity is that it is almost 

 always placed at the edge of the trypanosome, from which it seems to 

 protrude, or to be on the point of falling out. This is so marked that in the 

 laboratory this trypanosome became known as the " glad eye," from the well- 

 known play of this name. 



Undulating membrane. — Well developed and thrown into bold undulations, 

 herein differing from T. vivax and T. uniforme. 



Flagellum. — It is difficult to say whether this species has a free flagellum 

 or not. By careful staining and good illumination it would seem in most 

 cases as if the undulating membrane extended to the tip of the flagellum. 

 In most preparations, however, the last two or three microns of the flagellum 

 often appear to be free. This is shown in Plate 13. 



Division Forms. — In the monkey, in which these trypanosomes swarm in 

 enormous numbers, masses of them can be seen, sometimes filling up the 

 whole field of the microscope. It would seem as if multiplication took place 

 so rapidly that the individual trypanosomes had not time to disengage 

 themselves. A small part of such a mass is represented in fig. 1 in the text. 



Fig. 1. 



