COMPARATIVE HELMINTHOLOGY 
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I present a sketch of one of these heads as seen from above 
(No. 1, a), another as seen from the side (No. 1, b); in both of 
which the circlet of hooks can be seen, and also a view of detached 
hooks as the} 7 lie in different positions (No. 1, c). 
As the number of heads in a small cyst not larger than a pea 
was often five or six, and as the number of cysts in the single 
mass which you sent was over fifty, the whole number of heads 
in this portion above must be many hundred. 
Specimen No. 2 consisted of several cysts of variable size, 
attached to a common prelicle, and formed of connective tissue. 
Imperfect staining (on account of the specimen not being fresh) 
with silver nitrate, showed the existence of lymphatics, and a rather 
ioubtful appearance of an endothelial layer. On opening one of 
these cysts carefully, it was found to enclose another cyst whose 
contained fluid distended both. This latter one was free, and 
terminated in a neck, capped by a white head bearing the propor¬ 
tion shown in drawing No. 2, a. The thin membrane which 
composed the sac was not fresh enough to yield satisfactory results 
with silver nitrate. The fluid within the sac was of a dark brown 
color; it contained albumen in a small amount and considerable 
amorphous material; some imperfect crystalline forms, the nature 
of which I am ignorant of ; also mycelium of a form of fungus. 
The head was inverted, like the finger of a glove doubled 
partly outside in, which gave an external transverse fissure that 
could be penetrated by a fine needle. The head was filled with 
calcarious granules; as proved by the solution of carbonic 
dioxide on the addition of acetic acid. I must confess that I was 
unable to perceive a circlet of hooks, though the characteristic 
transverse rugae in the neck was very distinct, and the whole 
appearance shows conclusively that we have to do with a 
cysticercus. 
I am disposed to refer it to the cysticercus tenuicollis, on 
account of the variable and large size of the cysts, some of which 
were as large as a hen’s egg; also on account of the manner of 
growth and attachment resembling somewhat an ecchinococcus 
cyst, for which they have often been mistaken, as was long ago 
pointed out by Kiichenmeister. The form and appearance of the 
