172 THE CANADIAN HOESE 



middle humour, (crystalline lens,) or on its capsule, and is 

 variable in size, sometimes not larger than the head of a pin, 

 whilst in other cases it covers the whole lens. 



Causes. — It is generally a result of repeated attacks of 

 specific opthalmia, or it may even supervene upon a first 

 attack ; it may follow a severe injury to the eye. ' 



Symptoms. — The eyesight is, either partially or completely 

 gone, and when covering the greater part of the lens, it is 

 easily known by its pearly white appearance. When small, 

 it is somewhat difficult of detection ; the eye is smaller than 

 in health, and the pupil becomes greatly contracted when 

 exposed to light. It may be detected by placing the animal 

 in a bright light, and carefully examining the eye ; if the eye 

 appears smaller than the other, it indicates something amiss 

 with it. He should then be placed in a darkened stable, and 

 allowed to stand quietly for ten or fifteen minutes before being 

 subjected to an examination. Stand in front of him, and 

 bring a lighted candle close up to the front of his eye, when 

 any alteration in the structure of the lens can be readily 

 detected. 



Treatment. — In the horse is useless, as when permanently 

 established it cannot be recovered. When the cataract is 

 confined to one eye only, it interferes but little with the 

 horse's usefulness for ordinary work. 



FILAEIA (OE WOEM IN THE EYE.) 



In Canada the phenomenon of worm in the eye is of rare 

 occurrence ; in Britain it has never been known, but in India 

 it is a prevalent afi'ection amongst horses. We can best 

 illustrate our views on this subject by giving a brief descrip- 

 tion of the following case : — In the beginning of May 1864, 

 we were requested by Mr Armstrong of York township to 

 examine a horse belonging to him, and suffering from a 



