D. L. Maokinnon 
33 
boi’der of the trophonucleus. I saw no division stages among the 
flagellate individuals, nor any sign of so-called “ sexual ” forms. 
My recent experience of the extraordinary variability of the herpe- 
tomonad flagellates and their allies has made me very reluctant to 
assume from a few samples that my specimen is a true Grithidia, and 
not just a stage in the encystment of a Herpetovionas. Particularly is 
this the case with the flagellates found in the hind-gut, where, in the 
process of rounding off, a more or less crithidian-like stage is liable to 
be gone through by Herpetomonas itself I recognize, however, that 
the present flagellate possesses a slight undulating membrane ; accord¬ 
ing to Patton’s definition of the genei’a this character serves to 
distinguish Grithidia from Herpetomonas, even when the other test— i.e. 
the position of the kineto-nucleus relative to the trophonucleus—fails. 
The characteristic feature of G. campamdata consists in the bell¬ 
shaped encysting stages. PI. Ill, figs. 9—12 illustrate these, as I found 
them in the caddis-worms. Ldger and Duboscq describe them as 
attached in masses to the epithelial lining of the gut, with the mouth 
of each bell directed downwards. I never found the parasite so plentiful 
as Ldger and Duboscq figure it, and the “ bells ” were more often seen 
clinging to the bacterial tangles that almost block the intestine of the 
larva. The “ mouth ” of the bell seems to arise through the gradual 
broadening of the anterior end of the flagellate (PI. Ill, figs. 6—8) and 
the withdrawal and dissolution of the attaching flagellum, rather than 
by the encysting stages coming to lie on their sides, as Leger and 
Duboscq describe. 
Very small, rounded-off individuals measured only 3—4 yu, in length, 
but the final stage of the cyst was not seen. 
(c) Entamoeba, sp. 
In three larvae (Limnophilus 7'hombiciis) I noticed a few small 
amoebae moving about among the bacteria in the hind-gut. Text-figures 
2—5 were drawn from the living organisms. I did not succeed in 
staining them. The average dimensions of the amoebae were about 
12 fix 10 p. As will be seen from the figures, the form varies from 
oval to round, one end showing an even outline, while from the other 
break out several blunt pseudopodia. The endoplasm is very granular, 
and passes insensibly into the clearer ectoplasm. I saw no contractile 
vacuole. The nucleus appears as a small, clear, oval or circular area 
in the posterior portion of the body. 
Parasitology rv 
3 
