46 TIIK HORSE. 



arrived at the greatest perfection between the 15th and 55th 

 degrees of nortliern latitude. The mare is found capaldc of 

 generating her species as early as the second year of her exist- 

 ence ; but it is detrimental to her form, and the future energy 

 of her offspring, thus prematurely to tax the productive powers 

 of her frame. It would be far more profitable to delay this im- 

 portant function to the fourth or fifth year, when the outline 

 of her form approximates more closely to the adult, and the 

 vital energies of the animal economy become more confirmed. 

 Mares, in common with the females of many other quadrupeds, 

 are subject to a periodicjil appetency for the male, which in 

 them is termed horsing. The natural season of its first occur- 

 rence is from the end of March to July, and so providential is 

 this arrangement, that the foal will be produced at a time when 

 nourishment will be plentiful for its support. 



" Common assertion fixes the period of gestatioii, or the time 

 intervening between conception and foaling, at eleven months ; 

 but whether calendar or lunar months are to be understood is 

 not explained. This discrepancy will appear the more unsatis- 

 factory when it is recollected that eleven calendar months want 

 but two days of twelve lunar ones. No attempt has been made 

 in this country to resolve the question. In France, M, Tessier 

 endeavored to arrive at some degree of correctness as to tlie 

 average time of gestation by registering a large number of 

 mares. He proved that the term of eleven calendar months 

 was often exceeded by several weeks, and sometimes, though 

 less frequently, j^arturition took place within that period. 



" ' In 582 mares, which copulated but once, the shortest pe- 

 riod was 287 days, and the longest 419 ; making the extraor- 

 dinary difference of 182 days, and of 82 beyond the usual term 

 of eleven months.' Blaine's Yet. Outlines. 



" On another occasion an account was kept of the duration 

 of pregnancy of 101 mares. Of these : 

 3 foaled in 311 days. 



