BYCANISTES BUCCINATOR (the trumpeter hornbill). 
T rypanosomes.* 
Two distinct trypanosomes, one small and the other large, were 
seen in a bird of this species shot near Coquilhatville in the Congo 
Free State. The smaller trypanosomes (Plate XXIV, figs. 1,2,3, 4, 5,6) 
were by far the most numerous. Their appearance in stained 
specimens varies very considerably, so that it is possible to descnbe 
three distinct types, although forms intermediate between them can 
be distinguished. These may be called the “slender" (figs. 1,2), 
“ broad ” (figs. 3, 4), and “ stumpy ” (figs. 5, 6) forms, in accordance 
with their general appearance. To some extent the structure of these 
forms varies with their dimensions. The stouter forms usually stain 
more lightly, have the looser cytoplasm, have no vacuole at the 
posterior extremity, and their large nuclei do not extend completely 
across their bodies. 
This association of qualities is not constant, however, and all 
gradations were seen between forms possessing them and the, as a 
rule, darkly-staining and more compact slender forms. All these 
forms are, therefore, considered to be merely variations of one parasite, 
which may be described as follows: — 
The blepharoplast stains very densely and more darkly than eithe. 
nucleus or flagellum. Its position may vary from the extreme posterior 
extremity, in particular in the “ broad ” and “ stumpy ” forms, to a spot 
i/i or more from the end of the parasite (fig. 1). It is oblong in shape 
and is seen to be granular ; in several specimens at least four 
granules, sometimes arranged in pairs, can be counted (fig- 
Although the arrangement of these granules occasionally suggests 
commencing division, none of the ordinary longitudinal division forms 
were seen. The blepharoplast may be placed longitudinally, 
obliquely, or transversely in the parasite. Just anterior to it there is 
often a well-defined vacuole, or, when that is absent, a more lightly 
stained area. 
The nucleus frequently extends completely across the body of the 
parasite and is almost always surrounded by an area stained more 
lightly than is the remainder of the body. The relation between 
the size of the nucleus and the type of parasite varies considerably, 
* The description of this parasite is reproduced by permission from the Journo 
of Medical Research. \ ol. XVI, No. 5, March, 1907. 
