253 
these parasites a large vacuole was seen immediately in front of the 
blepharoplast. In this parasite the blepharoplast was comparatively 
large, and recalls the trypanosome seen at Eala. 
In the other cattle, Zilani (No. 8), Yolo (No. 9), and Keowkosiko 
(No. 60), the trypanosomes are of the “tadpole” variety. In Yolo, 
however, one parasite was seen of the “ long ” type with free flagellum 
and comparatively large blepharoplast. I he further history in sub¬ 
inoculations of the trypanosome derived from Yolo is of great 
importance in its bearing on the identity of these cattle trypanosomes. 
In the rat (Exp. 222), inoculated from Yolo, all three types were 
found. Of these the “ stumpy ” type, measuring from 15 to 18/x in length, 
was most abundant. In the subsequent passage this differentiation 
became more pronounced. The very short forms, measuring up to 
14/4 in length disappeared, but the other two types persisted. The 
num6er of “ long ” forms increased with the progress of the disease, 
as was noted by Dutton and Todd in the case of 7 rypanosoma 
dirnorphon (°, page 37). 
The remaining two types can still easily be distinguished in 
experimental animals. The “ long ” form is more plentiful, is slender, 
and has a rather acute posterior extremity. The flagellum is fairly 
long and is actively motile, whipping from side to side with great 
vigour. The movements of the whole trypanosome are active and 
progressive. The trypanosomes of the “ stumpy ” type are rather broad 
^d have a blunt posterior extremity. They move slowly, twisting 
round on themselves, then straightening out again, and so on. As a 
mle they maintain the one position and do not move from place to 
place. The undulating membrane moves sluggishly, and there appears 
to be no, or, at most, a very short, free flagellum. The body of the 
trypanosome is itself contractile. When buried between corpuscles 
{ be movements of both forms become appreciably slower. 
(t>) Trypanosomes of the Kasongo stallions 
In the younger horse the parasites were identical with the 
tadpole” forms as observed in the cattle. Unfortunately, no su 
ln °culations were made from this animal. 
In the second horse, “ Toul,” the trypanosomes were of the secon ^ 
‘ stum Py”) and third (“ long ”) types as seen in the cattle. 1 he long 
