C. Strickland 
87 
Eat No. 
No. of fleas 
Eesult 
20 
30 
42 
46 
60 
10 
1 
5 * * 
2 
It 
11 
1 
92—94 
124 
9 
31 
* signifies that one of these fleas was Pulex irritans and one Geratophyllus fasciatus. 
t C. fasciatus. 
Therefore 31 fleas taken from 9 different and apparently uninfected 
rats shewed no T. lewisi. 
G. The examination of organs, other than the alimentary 
tract, in lice and fleas. 
In fleas which had fed on infected rats, other organs than the 
alimentary canal were examined in a few cases to see if any forms of 
T. lewisi could be encountered in these organs. Thus the generative 
organs, the salivary glands, and the fat body were examined. The 
coelomic fluid was also carefully examined. In none of these tissues 
could any traces of T. lewisi be discovered. I also dissected out the 
oesophagus of a few fleas, as this part of the alimentary tract was not 
removed when the midgut and the posterior parts of the intestine were 
examined. In the oesophagus, T. lewisi was never found, and the 
trypanosomes do not appear to migrate from the midgut forwards. 
Similarly, in lice, which were collected from infected rats, the 
generative organs, the fat-body, the coelomic fluid and the oesophagus 
were prepared and examined, but no form of T. lewisi was encountered. 
H. Notes on the occurrence of Crithidia ctenophthalmi. 
In 8 fleas (Ctenophthalmus agyrtes ), from 5 different rats infected 
with T. lewisi, I found Crithidia ctenophthalmi. This flagellate was 
almost invariably found massed in dense rosettes in the dilated upper- 
part of the hindgut just below the openings of the Malpighian tubes, 
but tufts of them or single flagellates sometimes occurred as far down 
the gut as the rectum. Their movement was a lashing to and fro of the 
