DISEASES PECULIAR TO BREEDING STOCK. 295 



upon the eye, which was thus kept inflamed and running for 

 a length of time during the course of pregnancy. The pro- 

 geny a filly had the eye on the same side defective and 

 represented by a small, opaque black mass. The dam recov- 

 ered and afterward bore colts with sound eyes, as did also 

 the one-eyed filly in due course of time. This but expresses 

 a general law that the disorder which is active and causes 

 suffering at the time of reproduction is most likely to tell 

 injuriously on the progeny. When, therefore, all the pro- 

 geny inherit a constitutional predisposition to moon-blind- 

 ness those which are begotten or born during a period of 

 active disease and suffering on the part of one or both parents 

 are most likely to become psrmanently blind. Another dom- 

 inating cause of moon-blindness is the occurring in the pre- 

 disposed animal of debility or weakness from any influence. 

 It may be safely assumed that whatever undermines the gen- 

 eral health or lowers the hardy vigor of such predisposed 

 animals tends to bring on the disease. Thus coarse, fibrous, 

 or innutritious fodder often acts in this way. An exciting, 

 over-stimulating diet acts in the same way. An animal that 

 keeps sound on a diet of oats or barley may fall a victim if 

 fed on Indian corn. Overwork or the combination of hard 

 work and a diet insufficient to repair the excessive waste is 

 equally injurious. Debilitating diseases of all kinds are 

 equally liable to superinduce the malady. An attack of 

 influenza, a chronic indigestion, or the presence of worms in 

 the stomach or bowels, may be the immediate cause of moon- 

 blindness, one without which the hereditary tendency might 

 have remained latent. Some causes, however, deserve more 

 special attention because of their general operation or more 

 wide-reaching effects. 



It is notorious that certain countries and districts suffer 

 more from recurring ophthalmia than others. In a general 

 way it is the more moist and relaxing that furnish the most 

 victims. The West of England and the whole of Ireland 

 furnish more subjects of ophthalmia than does the dry east- 

 ern coast of Great Britain. The damp, marshy and cloudy 

 region to the north of the Pyrenees suffers badly, while in 

 the dry, clear atmosphere of Catalonia, to the south of these 



