Account of a Filaria in a Horse’s Eye. 281 
These cysts appear, when examined with a lens, not exactly 
ovoid, but irregularly contracted towards one extremity, so as to 
form a kind of short neck. ‘These are dispersed throughout the 
the muscles over the body, and are placed in the direction of the 
fibres, in the cellular membrane, immediately investing the mus- 
cular fibrille, or the tendinous fibres to which they are attached. 
In a recent specimen, one and sometimes two thread-like worms 
may be seen, coiled up in each cyst. Mr. Owen regards this an- 
imal as closely allied to the eels which are found in paste and 
vinegar, and has given it the name of Trichina spiralis. It is 
very probable that some anomalous diseases may be occasioned 
by the great multiplication of these worms, while the cause is 
unsuspected and inexplicable. 
he most common worm met with in the different ‘indie of 
animals, is the fluke, or Fasciola hepatica, which is sometimes 
also foundin man. We find it in cattle, sheep, swine, and deer; 
in reptiles, fishes, and even worms of the largest kind ; and it is ~ 
this which occasions the disease called the rot in sheep. Leuwen- 
hoeck counted 870 of these animals in one liver. Hydatids are 
also found in sheep, in the brain and liver, and often carry off 
whole flocks. This is also met with in man, swine, deer and 
oxen, of which there are three different species, viz. cerebralis, 
vervecina, and ovilla.- It is unnecessary however to go into de- 
tail, in relation to the different species of parasites which inhabit 
the different races of animals ; it must suffice to state, that they 
are extremely niinisromaaothes though some are common to sev- 
eral species, = ane in general, each has its peculiar parasite ;— 
and, moreover, that probably each texture and organ furnishes a 
habitation for a distinct race of inhabitants. To this it might be 
added, that many of these parasites have parasites of their own, 
so that they are literally paid in their own coin. — 
It has been remarked that the F%/aria belongs to. the order Ne- 
matoidea of Rudolphi. ‘This order embraces those animals whose 
external skin is more or less furnished with muscular fibres, and 
usually striated transversely ; containing an abdominal cavity, in 
which is a distinct intestinal canal, extending nearly the whole 
length of the body. The intestine is connected with the neigh- 
boring parts and the general envelope of the body by numerous 
threads, considered by some writers as vessels for the conveyance 
of the nutritious fluid, and by others as ¢rachee, but without suf- 
