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the ears. I have had cases in bulls, especially young ones, where the 

 aqueous humour has been rendered opaque, in fact, nearly milky 

 white, from excessive sexual exertion. The animal must not be used 

 in the meantime, but be kept perfectly quiet, in a dark loose box, and 

 the eyes bathed for 15 to 20 minutes, several times a day, with cold 

 water. 



635. Cataract is a pearly white appearance, or opacity, of the 

 crystalline lens, or its capsule, or both. It may result from external 

 injury to the eye, or from frequent attacks of inflammation, or periodic 

 opthalmia ; again, it may be congenital, and may appear in one or 

 both eyes. The whole, or only part of the lens may be affected, and 

 various names are accordingly given to it, such as Lenticular Cataract — 

 when the lens itself is the seat of the affection ; Capsular Cataract — 

 when only the capsule is affected ; and Capsttlo-Lejiticnlar — when both 

 are implicated. Old dogs seem to be the greatest sufferers, and in 

 these, it generally comes on gradually. In the human subject, the 

 lens can be removed, and suitable glasses substituted ; but in the 

 domestic animals, treatment is of little use. When the eye is injured, 

 or undergoing severe inflammation, the great point is to use every 

 endeavour to prevent a cataract forming. 



636. In examinations of horses for soundness, it is of the greatest 

 importance that the eyes be carefully examined, as cataract causes 

 partial or complete blindness. The horse must be taken into a dark 

 place, and the eye examined with a lighted candle ; if the eye is 

 correct, the pupil will contract gradually, on the light being 

 presented ; a clear, deep, black-blue, liquid appearance will be seen 

 beyond the pupillar space, and the image of the light from the candle 

 be reflected in three distinct places. On moving the candle to and 

 fro, the reflected lights move at the same time, but if cataract be 

 present, the pupil remains stationary, and a pearly white substance is 

 seen, filling up the pupillary opening. 



637. Amaurosis. — This, strictly speaking, is not a disease of the 

 eye itself, but a derangement of the "optic nerve," producing partial, 



