Account of a Filaria in a Horse^s Eye. 283 



3. Filaria gracilis is found in apes and monkeys in great 

 abundance. It grows to a length of ten or twelve inches, is 

 about as thick as a fine thread, head obtuse, and tapering sHghtly 

 at both extremities. 



4. Filaria attenuata. This species is found in the abdominal 

 cavity of crows, also in the cornea of the eye of fishes. It is 

 from one to six inches long, and obtuse at both extremities. 



5. Filaria ohtiisa inhabits the intestines of swallows. Its head 

 is somewhat acute, tail obtuse, body comparatively thick and 

 elastic, and has been found twelve inches in length. M. Ru- 

 dolphi has traced out its intestinal canal and ovaries. 



6. Filaria truncata. This^ species is about five inches long, 

 has a truncated head, a tail somewhat thick, obtuse, terminated 

 by a very sharp point ; inhabits the larva, or caterpillar of cer- 

 tain species of moths. ( Tinea padella.) 



7. Filaria ovale. This species formerly went under the name 

 of Gordius piscium, (hair-worm of fishes,) because it is found in 

 the liver of the carp. It is three or four inches in length ; head 

 oval ; tapering forwards ; tail round. 



8. Filaria capsularia. From half an inch to an inch long, 

 and resembles in thickness a middle-sized thread. The borders 

 of the mouth are recurved, resembling, according to De Blain- 

 ville, the mouth of a pudding-bag ; tail obtuse, papilliform, and 

 ending with a fine, sharp point. It occurs of both sexes, with a 

 large intestinal canal and stomach. The female is more gross — 

 often met with in the herring, in large quantities. It is very te- 

 nacious of life, for Rudolphi states that he has known it live 

 eight days in a dry place, and even to revive after having been 

 long frozen in masses of ice. It is this species which Zeder and 

 some other naturalists have formed into a genus, under the name 

 of Capsularis. 



9. Filaria papillosa. The Filaire equi of Gmelin, and the 

 Gordius equinus of other writers. This is the species which in- 

 habits the eye of the horse. It is from one to seven inches in 

 length, and about one-third of a line in diameter. It is usually 

 of a yellowish white or ash color, — sometimes of a brownish hue. 

 Head slightly obtuse ; mouth orbicular ; neck studded with pa- 

 pillas ; tail slender and curved. It occurs in different parts of the 

 horse, chiefly in the muscles and intestinal canal, though it has 

 been detected in the brain, as well as the aqueous humor of the 

 eye. 



