NATURAL HISTORY OF THE H0R8R. ^T 



being exceedingly small, but capable of absorbing ink by capil- 

 lary attraction. No such tubuli have been traced in the enamel. 

 The teeth, both incisors and grinders, are being constantly 

 worn away at the crown ; but the loss is supplied by the gradual, 

 continuous, and equivalent growth from the root. The horse's 

 teeth are sometimes, but not frequently, subject to disease. It 

 is seldom that any of them are lost from age, as is the case with 

 man, and most other animals. 



It has been remarked, that the constitution of horses and 

 men may be considered as in an equal degree of perfection 

 and capability of exertion, or of debility and decay, according 

 as youth or age preponderates. Thus, the first five years of 

 a horse may be considered as equivalent to the first twenty in 

 man ; or thus, that a horse five years old may be comparatively 

 considered as a man of twenty ; a horse of ten years, as a man 

 of forty ; a horse of fifteen, as a man of fifty ; a horse of twenty, 

 as a man of sixty; of twenty-five, as a man of seventy; of 

 thirty, as a man of eighty ; of thirty-five, as a man of ninety. 

 So far from this comparison being in favor of the horse, it may 

 rather be regarded as too little. Horses of thirty-five years 

 of age are as common as men of ninety, provided it be taken 

 into account that there are twenty human subjects for every 

 horse ; and, unquestionably, a horse of forty-five is less rare 

 than a man of one hundred and ten. 



To this it may be added, that the early English racers 

 appear to have been more addicted to longevity than those 

 of modern days, and the American horse generally than the 

 English ; probably because, in the former case, the horse waa 

 not put to hard work until his powers were developed by an 

 advance toward maturity. Two and three year old training 



