Parasites of the Eye. 445 



The demodex folliculorum invades the Meibomian glands of 

 the dog (Railliet), horse (Wilson) and sheep (Oschatz). These, 

 too, may be successfully treated by mercurial ointment. 



The silky trombidium has been found in the canthi and along 

 the margins of the lids in dogs in summer and may be treated in 

 the same way. Wood ticks (ixodes) also attack the eyelids. 



Lfeeches. The horse leech (Hsemopis Sanguisuga) has 

 been found on the conjunctiva of the horse in Algiers (Bizard). 

 Guyon had previously noticed a similar occurrence in the eye of a 

 soldier in the same country. 



Cysticercus Cellulosa. This larval cestode is not infrequent 

 in the orbit or even in the eyeball of pigs which are otherwise in- 

 fested by it. Its common habitat is under the mucosa of the eye, 

 where it appears as a white ovoid body as large as a barUy grain. 

 It may also be felt if not seen in the muscles of the eyeball or 

 between them 



Nordmann describes four cases of its presence in the interior of 

 the eye, twice in the anterior chamber, once in the posterior 

 chamber accompanied by cataract, and once in the vitreous, as- 

 sociated with blood extravasation and calcified sclera. Gescheidt 

 records two cases, of which one was in the anterior chamber and 

 one between the choroid and retina. Van der Hoeven records an 

 additional case of this kind. 



Cunier found a cysticercus beneath the mucosa in the outer 

 angle of a dog's eye, and Heincke found one in the orbit of a 

 fourteen day old colt, which had the eye atrophied. In these 

 cases the species is left uncertain. Finally Hutchinson found a cyst 

 in the anterior chamber of a horse's eye but failed to find any head 

 of a cestode. The double membrane constituting the walls, and 

 the tran.slucency of these and the contents suggested cystic tape- 

 worm, while the ab.sence of the head would be in keeping with 

 the brood-capsule of an echinococcus. 



Trichina. The ocular muscles, in common with those of other 

 parts of the body, harbor the trichina spiralis, but the presence of 

 the para.site cannot be certainly diagnosed during life unless the 

 trichina harpoon is used. Swelling and congestion of the con- 

 junctiva, and epiphora associated with general stiffness, and 

 irritable bowels may be present in such cases. 



