TRYPANOSOMES IN TSETSE-FLIES AND OTHER DIPTERA, 247 
panosomes were found in the fresh state. Smears were made 
and put by for examination. In the smears of two flies 
no trypanosomes were found ; in a third fly they were found 
in the smears of red blood, not in the black; in the fourth fly 
they were found both in the red and the black blood. The 
trypanosomes were slender and stout forms perfectly typical 
in character (figs. 51-55), the former scarce, and some of the 
latter dividing. In a smear from one tly 66 stout (6 dividing) 
were counted, but no slender; in a smear from the other fly 
28 stout, of which 11 were dividing, and 4 slender were 
counted. The high proportion of division-stages is remarkable. 
Nov. 19th.—The remaining Stomoxys, 20 inall, were dis- 
sected and examined, but no trypanosomes were found in any 
of them. 
Mansonia Hxperiments. 
Noy. 19th.—Two mosquitoes (Mansonia sp.) were fed 
on Monkey 478. 
Nov. 20th.—One was dissected and somewhat hastily exa- 
mined without any trypanosomes being noted. In the smears, 
however, trypanosomes were found abundantly, of pronounced 
slender and stout type (figs. 56-60). In one smear 120 stout 
and 60 slender were counted; in another, 78 stout, 54 
slender ; no dividing forms were seen. 
Nov. 20th.—One Mansonia was dissected, but no try- 
panosomes were found, and unfortunately no smears were 
made. 
Teniorhynchus Experiments. 
First batch, Nov. 19th.—Four mosquitoes (Tenio- 
rhynchus sp.) fed on Monkey 478. 
Nov. 20th.—'T'wo dissected ; in each active trypanosomes 
were noted. In the smears numerous typical slender and 
stout forms were found (figs. 61-65). Very few were dividing. 
In one smear were counted 78 stout, 41 slender forms (of 
which 4 were dividing); in another smear, 89 stout, 45 
slender (1 dividing). 
Noy. 21st.—Two dissected; a few rare active trypano- 
