Account of a Filaria in a Horse's Eye. 285 



and disclose a great number of living animalcules, of the genus 

 Monas. 



The accompanying 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 most 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.* 



Instances of the occurrence of Filaria in the human eye, have 

 been recorded by different authors. In a late German medical 

 periodical, [Zeitschrift fur die gesammte Medicin,Feh. 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 1768, observ- 

 ed a 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 obliged to be secured by a 



^It is now a well ascertained fact that animals not only inhabit vegetables, but 

 that vegetable growths are sometimes observed in the bodies of living animals. 

 The most remarkable example of this, perhaps, is that of the "vegetating wasp" 

 of our Southern States and the West Indies. The insect, which is a species of 

 Pohjstrix, is infested, while alive, with a parasitic fungus allied to Sphccria, which 

 gradually 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 second gen- 

 eration succeeds, which is cut off in the same manner, and so on. Similar instan- 

 ces have been observed among other insects, in all stages of their development. 



Vol. XXXIX, No. 2.— July-September, 1840. 37 



