Predisposing Causes of Roaring. 51 



With regard to the latter remark, as to sire and dam 

 being sound in their wind and their progeny Roarers, this 

 might admit of another explanation than that of size, and 

 inquiry would probably elicit the fact that a progenitor of 

 one or other parent was a Roarer. Atavism is not at all a 

 rare occurrence in the equine species, and there are 

 instances, to my knowledge, which would go to prove that 

 a predisposition to Roaring may be transmitted indirectly 

 and collaterally. 



Some years ago, it was asserted that heavy cart-horses in 

 England and Scotland were almost as liable to become 

 Roarers as thoroughbreds, while roadsters and hackneys 

 seemed to suffer least ; and in Paris it was stated to be the 

 same. So far as I can ascertain, this is not the case 

 nowadays. 



Though it is a fact that large horses are more predis- 

 posed to become affected than small ones or ponies, yet size 

 cannot be looked upon as nearly so important a factor as 

 the other influences we have been considering. Eastern 

 and Southern horses, natives of warm, dry climates, are 

 small when compared with those of the West and North, 

 which are reared in a cold and damp atmosphere, and kept 

 generally in hot, close dwellings, which engender diseases of 

 the respiratory organs. But even among the large horses 

 there are such notable exceptions to this predisposition, as to 

 show that height and weight are not so important as some 

 authorities would lead us to believe. 



Among army horses, the largest are to be found in the 

 Artillery and Transport, the smallest and lightest in the 

 Cavalry ; and yet it is in the latter that most Roarers are 

 reported. Table II. (p. 37) shows this ; but it likewise 

 affords evidence that the larger horses of Heavy Cavalry 

 are more affected than those of Light Cavalry. 



Charon carefully noted the sizes of horses purchased for 

 the French army during four years, and found that the per- 

 centage of Roarers among those of the Artillery was only 097, 



4—2 



