52 
likely that it is caused by a multiplication and separation 
of young individuals, which break down and leave the 
host’s cells, the intercellular nature of the adults being 
the only point in which the diffuse infiltration here differs 
from its occurrence in the Glugee. 
Anyhow, in these, to return to (B), the final result 
is that the infected area consists of a confused mass of 
tissue-cells (many broken down), spore-containing cells, 
and clusters of free spores. In A on the other hand, this 
process is not evident, and I greatly doubt whether it has 
been at work. Probably owing to the strong infection, 
with its attendant effects on the host’s metabolism, the 
parasites do not seem to have attempted to spread further 
(except, as it were, automatically by growth), but to have 
concentrated their energies on becoming large spore- 
forming individuals. The cysts are well-defined, and 
sharply limited, and there is no sign of “ diffuse 
Ausliiufer.” Each is, I consider, the result of growth of 
a single individual. 
Doflein (l.c.) is of the opinion that the cysts of G. 
lophii, which he describes (p. 334 et seqg.), result from the 
fusion of 3-4, and this may well be, for he is evidently 
dealing with “ pseudocysts” and an infiltration con- 
dition, more or less similar to my specimen B. In A, 
however, the minute structure shews clearly that each 
cyst is a single unit. [ere the parasites are never, as 
sometimes in Hagenmiiller’s case, in the muscles, but 
entirely in the areolar tissue of the sub-mucosa. The 
intestinal epithelium is also free from infection, and 
though often broken round the much-enlarged internal 
end of the folds or ruge, it is still quite evident and 
normal up the furrows. For a general idea of the size 
and arrangement of the cysts, the reader is referred to 
Johnstone's fig. 2, Pl. D. 
