ON THE TRYPANOSOME OF THE LITTLE OWL. 
151 
to the first type mentioned, was also noticed at this time; 
it was recognised by its movement, but as it was more or 
less surrounded by a clump of corpuscles, its characters, with 
the exception of its approximate size, could not be made out. 
Looked at again later (about noon) the small trypanosome was 
found to have detached itself, and was wriggling feebly, 
loose, and waving its flagellum about slowly; it appeared 
moribund. At 2 p.m. it was nearly dead, only the tip of its 
flagellum now moving* feebly. 
The same three types of individual were also found in the 
bone-marrow of later owls (Nos. 13 and 14) ; and here 
again, in the latter bird, certain trypanosomes were seen to be 
distinctly attached. A medium-sized, slender form (belong- 
ing to the first category) was attached to a corpuscle by its 
flagellum, by means of which it was waving the corpuscle 
about vigorously. Further, a small trypanosome (type 3) 
was seen unmistakeably attached by itsflagellum toaleucocytic 
cell; and another small individual also appeared attached, 
but this could not be ascertained with certainty owing to the 
parasite being partially hidden. These observations were 
also made in the evening, about 8 p.m.; aud the above two 
individuals were watched at intervals until midnight without 
any change being noticed. Next morning the slender form 
could not be found again; while the small individual was 
quite motionless and seemed to be dead. 
From the above notes the following definite and rather 
interesting points may be emphasised. The slender, medium- 
sized parasites, and also the small, stumpy forms, may be 
found attached to a cell, either by the flagellum or by the 
aflagellar end. On the other hand, no individual belonging 
to the large, sluggish type (of the second category) was ever 
observed attached. 
In owl 23 quite a different state of affairs was met with 
from that obtaining in the earlier owls. The trypanosomes 
in this bird were in what we propose to refer to as the 
“ summer condition ” — both as regards the habitat of the 
parasites and the type of form found. This condition is to be 
