Account of a Filaria in a Horse’s Eye. 285 
and disclose a great number of living animalcules, of the genus 
onas. 
The ‘aceompanying ‘magnified sketch will represent. the form 
of this animal with sufficient exactness. 
Achtheres percarum. 
Of the worms which Nordmann describes as infesting the eyes 
of fishes, five out of seven are attached to different species of 
perch. Kirby conjectures that as these constitute the mcst nu- 
merous body of predaceous fishes in rivers, the object of this sin- 
gular provision is to impair their organs of vision, so that the 
roach, dace, carp and tench tribes may not be entirely destroyed.* 
Shetesces: of the occurrence of Filaria in the human eye, have 
been recorded by different authors. In alate German medical 
periodical, (Zeitschrift fur die gesammte Medicin, Feb. 1839;) 
several cases of this kind have been recorded. Blot of Martinique 
saw two worms in active motion under the conjunctiva, which 
he removed by incision. One of these, which was sent to M. 
Blainville, was thread-shaped, thirty-eight millimetres long, with 
a black protuberance adapted for suction. Bajon, in 1 768, observ- 
eda Filaria in the eye of a negress, which kept in a continual ser- 
pentine motion” without producing pain; but it caused a constant 
epiphora, or watery secretion. When an incision was made the 
worm went to another part, and was 8 obliged to be secured by a 
oa : 
*Jt is now a well ascertained fact that a not only st vegetables, tae 
that vegetable growths are so metimes observ n the bodies of living animals. 
The most rémarkable example of this, fare y is ee of the “vegetating wasp” 
of our Southern States and the West Indies. The insect, which is a species of 
Polystriz, is infested, while alive, with a parasitic fungus allied to Spheria, which 
gradually i increases so much in size as to destroy the life of the animal, which 
having deposited its eggs in the plant, perishes ; when, in due time, a satoiil gen- 
eration succeeds, which is cut off in the same manner, and soon. Similar instan- 
ces have been observed among other insects, in all stages of their development. 
Vol. xxx1x, No. 2.—July-September, 1840. 37 
