the hippomanes, though the antients assert that she instantly devours it.It is usual to cover a mare nine days after she has foaled, that no time may be lost, and that every possible profit may be derived from the stud. It is certain, however, that her strength being divided, she is unable to nourish both a foal and a foetus so successfully as if she had but one at a time. To procure excellent horses, therefore, the mares should be covered but once in two years, which would make them live long|er, and hold more surely; for, in ordinary studs, it is well if a half or two thirds bring forth in a year.Mares, though impregnated, can suffer to be covered; and yet there are no instances of su|perfoetation. In general, they are capable of producing to the age of 14 or 15 years, and the most vigorous produce not after 18. Stallions, when properly managed, retain their prolific powers to the age of 20 years, and sometimes longer: And, as in man, those which began too early are soonest extinguished; for the large horses, which come sooner to maturity than fine ones, and are employed as stallions at the age of four years, are commonly useless at 15.The life of horses, as in every other species of animals, is proportioned to the time of their growth. Man, who grows 14 years, can live six or seven times as long, i. e. 90 or 100. The horse, whose growth is accomplished in four 0