C. M. Wenvon 
353 
monas from the blood and tissues of the chamaeleon, for it would seem that 
in this animal the intestinal infection may indicate the path by which the 
blood infection of the gecko was acquired. 
The exact relation of the flagellates of the chamaeleon to the mucosa is 
best studied in sections. It is found that the infection is a very large one and 
that all the glands of the cloacal mucosa have their ducts packed with the 
organism (PI. XIX, Fig. 1). No trace of invasion of the cells could be found, so 
it would appear that the flagellate is limited to the ducts of the glands and the 
surface of the mucosa. Fig. 2 shows a single gland more highly magnified and 
though many goblet cells are present there is no tendency for the flagellates to 
make their way into these. There was no evidence that the flagellate in any 
way inconvenienced its host. 
Source of the infection. 
As was suggested by Bayon (1915), the most probable source of infection 
would appear to be some insect which the chamaeleon has eaten. Flies could 
very readily infect themselves by feeding on the mucus covering the faeces 
passed by the chamaeleon, which in its turn could be infected by eating an 
already infected fly. Such a hypothetical cycle would seem to be the prob¬ 
able one. 
The contents of the stomachs of chamaeleons were examined with a view 
to identifying the flies on which they had fed, but little information was ob¬ 
tained, chiefly through lack of time to follow the observations properly. How¬ 
ever, some experiments were conducted with the ordinary house-fly, Musca 
domestica. Pupae were collected and it was found that the flies hatching from 
these were free from flagellate infections. A batch of these hatched flies was 
fed on the infected mucus from the chamaeleon’s cloaca and kept alive by 
feeding on sugar and water. Another batch was used as control and kept 
alive in a similar manner. 
24. vi. 16. Flies fed on infected mucus. 
25. vi. 16. Several flies examined. 
1. Stomach with large infection of very active flagellates. 
2. Ditto. 
3. Active flagellates in stomach and rounded forms in intestine. 
4. Active flagellates in both stomach and intestine. 
5. Doubtful forms seen. 
6. Ditto. 
7. Rounded forms in intestine. 
8. Active flagellates in stomach and round form in intestine. 
9. Ditto. 
10. Active forms in stomach and intestine. 
26. vi. 16. One fly had resting forms in intestine. 
30. vi. 16. Four flies all negative. 
1. vii. 16. Thirteen flies all negative. 
