608 THE DISEASES AND DISORDERS OF THE OX. 



lachrymal gland, from which they are conveyed to the eye by the 

 medium of the lachrymal duct. 



In reference to inflammation of the eye, we must remember 

 that the cornea, or sclerotic, or the choroid, or the iris, or the 

 retina, or, indeed, almost any part, may be inflamed. We shall 

 treat of the common forms, conjunctivitis, corneitis, iritis, and 

 retinitis. 



Ophthalmia or conjunctivitis is a very frequent and sometimes 

 a very severe disease in sheep. Many members of a flock 

 become quite blind ; but though they may be quite unable to 

 see, still very few of them will stray away and lose their com- 

 panions. Usually they follow the rest of the flock by means 

 of their power of scent, and a touching example of the friend- 

 ship and kindliness of disposition of sheep for one another ifr 

 aff'orded by the fact that *' a friend generally attaches itself to 

 the sufferer, waiting on it with the most tender assiduity, and 

 by its bleating calling it back from danger and from going 

 astray." (Hogg on Sheep, p. 118.) To those who believe in 

 the doctrine of metempsychosis, the brotherly affection and 

 solicitude which subsist among certain lower animals, and of 

 which this illustration may be taken as an example, must in 

 some degree alleviate the feelings of horror and apprehension 

 which otherwise, we might imagine, they could not but feel at 

 the idea of their individualities being at some future time possibly 

 merged into, or, rather, identified with, that of any lower 

 animal — it may be that of a sheep or a goat perhaps — though, 

 it is to be hoped, not that of a sloth or a pig. 



This disease is frequently traumatic in origin, at other times 

 apparently not so. In either case there may be, and generally 

 is, corneitis in addition. 



In cases of conjunctivitis, the conjunctiva lining the eyelids 

 is deep red in colour, and has a heightened temperature. The 

 cornea may also be inflamed at the same time, especially when 

 the inflammation arises from the presence of hay-seeds, or 

 wheat-husks, or other like substances under the eyelids, or from 

 injuries of any kind. In man the cornea is not usually affected 

 when the conjunctiva is, though it may be sometimes. At the 

 same time, the pulse-rate may be accelerated, the mouth hot, 

 the appetite and the chewing of the cud impaired. The animal 



