TRYPANOSOMIASIS EXPEDITION TO SENEGAMBIA 
55 
estreld) very common in Senegambia. One was found to be infected out of twenty- 
five birds of different species, for the most part belonging to genera Estrelda and 
Crithagra, examined in the laboratory in August. These birds came from Bathurst, 
Gambia, whence they had been sent in May. 
Only two to four parasites were seen in a coverslip preparation. In fresh 
preparations the parasite appears as a very actively moving spirillum-like body ; so 
striking, indeed, is this resemblance, that at first sight it was thought to be a true 
spirillum. The undulating membrane is scarcely recognizable, and the parasite 
has no free flagellum. When its movements have become slower, the organism is 
seen to possess a long straight body pointed at both ends. At a point about one- 
third of its length distant from the posterior end of the parasite is seen a retractile 
spot, the micronucleus. A little further on, a slightly refractile area indicates the 
position of the macronucleus. When the parasite is stationary for a moment, waves 
of movement commencing at the anterior end travel down to this refractile area and 
there cease. The part of the body posterior to this spot remains perfectly quiescent. 
The parasite generally moves with the end remote from the refractile spot in 
front. Careful examination reveals the presence of a very narrow undulating- 
membrane, commencing at the micronucleus and running along to the anterior end 
of the organism. No free flagellum could be made out in fresh specimens. The 
protoplasm of the organism was apparently homogeneous. 
In stained preparations, Plate II, fig. i, the above details are better seen. 
Along the free border of the undulating membrane runs the flagellum, stopping 
abruptly at the anterior end of the organism in a small red dot. The macronucleus 
is elongated, granular, and does not quite extend across the short axis of the parasite. 
The micronucleus is a small dot or oval spot of chromatin surrounded by a small 
halo. The protoplasm takes on a uniform blue colour. The length of the parasite 
varies from 36 /ul to 38 and its width at the macronucleus is 1-4 /u to i*6 
The distance from the micronucleus to the posterior end is 10*4 Distance from 
the micronucleus to the centre of the macronucleus is 9 m to 10 jul. No develop- 
mental or dividing forms were seen in any preparation. 
Two larks were inoculated, each with 0-5 c.c. of blood from this bird, but so 
far parasites have not been seen in the blood of either. 
Trypanosoma. — Spec, incert. This parasite was fairly common in the blood of 
species of Crithagra and Estrelda, both at St. Louis and Bathurst, though they were 
never present in large numbers.* 
At St. Louis out of fifteen birds examined seven were infected. 
At the most three to six parasites were seen in a preparation. In the fresh 
film the parasite is a verv stumpy organism which moves sluggishly in the blood. 
* The popular name commonly given to these birds is ' millet eaters.' This name includes several varieties called Hec 
corail, cordon bleu, ventre rouge. The majority of the birds examined were of the first. 
