95 
several hours, only the contents from the deeper portions of 
the tumours being used. 
For the purposes of the experiments both Musca domestica 
and Stomoxys calcitrans were bred artificially and the cultures 
kept going in the laboratory. 
e culture of Stomozys calcitrans was kept going for 
twelve months, when it was allowed to die out. The flies 
Where contamination by ng was exclu 
4 estica was fed on a mixture of horse serum, 
= n ater, and was allowed to deposit its eggs on 
rvae, a 
Important to regulate the number of fly larvae developing 
m a culture. 
e stomachs were sometimes examined a few hours after 
obtained of the number of species present. Only in one case 
to 
commonly present than was at first expected, and in most of 
the stomachs examined could be found, although often only 
Habronema muscae was 
blood in the body of the worm. Chemical tests for blood were 
3 obtained with extracts from these worms. 
