50 THOMPSON YATES AND JOHNSTON LABORATORIES REPORT 
VII. OTHER FORMS OF FLAGELLATA FOUND IN SENEGAMBIA 
In the course of our examination of a large number of small animals and 
birds, we observed some ten varieties of flagellates, for the most part belonging to 
the family Trypanosomidae (Doflein). These organisms occurred in the blood of 
frogs, small birds, tortoises, and in the African house mouse. 
We were not able to make any serious attempt to ascertain the life history of 
these parasites. It is probable that a study of the trypanosomata, parasitic in lower 
animals, will throw light on obscure points in the life history of those species pathogenic 
to man and the higher animals. Such a study, in the case of other parasites, has met 
with most fruitful results, notably so in malaria. For this reason, we here present 
a short description of the forms we have seen in fresh blood, and of their appearance 
in film preparations, stained by Romanowskv's method. 
Trypanosomes in Frogs 
Trypanosoma sanguinis, Gruky, 25 1843. 
A parasite was frequently seen in the blood of African frogs corresponding to 
that first described by Gruby in 1843, and called by him T. sanguinis. Out of 
twenty-nine frogs examined, including Rana trinodis (?) and other species, this parasite 
was seen m the blood of fourteen. The parasites were never encountered in any 
great numbers in either the peripheral or central circulations of the infected frogs. 
At the most four to six were seen in a preparation. 
This parasite has been described in the living state by Ray Lankester 45 as 
a minute pyriform sac, with the narrower end bent round on itself somewhat spirally, 
and the broader end spread out into a thin membrane which is produced on one side 
into a very long flagellum. The wall of the sac was striated coarsely as in Opa/ina y 
and the direction of the striae on the two sides of the sac, as seen one through the other, 
showed that the small end of the sac was twisted as well as bent over on itself. A 
pale clear nucleus and a very few granules were also seen. In life, the broad membrane 
undulates vigorously in a series of waves, the flagellum taking part in the movements. 
The series of waves of the undulating membrane are not incessantly in one and the 
same direction. In stained preparations (Romanowsky method) the simplest form 
of the parasite seen is represented in Plate 11, fig. 3. 
This parasite differs from other trypanosomes seen in frogs, in that 
there is no definite line of demarcation between the body proper and the undu- 
lating membrane. The protoplasm of the body takes on a deep bluish purple tint 
