Aristotle's History of Animals / In Ten Books

by Aristotle

Chapter XXI.

1. The cow is impregnated with a single act of coition, and the bull mounts upon her with such violence that she bends beneath his weight. If he fails to impregnate her after twenty days, she is again admitted to the bull. Old bulls will not mount the same cow several times in the same day unless there is some intermission, but young bulls, incited by the strength of their desires, will force the same cow several times, and will mount upon many in succession. The bull is one of the least lascivious of animals. The conqueror copulates with the female, but if he become impotent from frequent sexual intercourse, the inferior will attack him, and often prevail.

2. Both the male and the female commence sexual intercourse, so as to produce young, at a year old, though not generally till they are a year and eight months old, or two years old according to general agreement. The female is pregnant nine months, and produces her young in the tenth month; some persons affirm that parturition takes place at ten months to a day; if any of them calve before the above mentioned time, the calf is abortive and does not live, and even if born a little before the proper time it cannot live, for the hoofs are imperfect. The female generally produces one at a time, sometimes two. She continues to bear and to have sexual intercourse as long as she lives.

3. The female usually lives fifteen years, and so does the male if he is not castrated; some live for more than twenty years if they have an active body. They usually place castrated oxen as leaders of the herd, as they do in sheep, and these live longer than the others, for they do no work, and feed in a superior pasture. They attain perfection at five years old, wherefore some say that Homer was right when he spoke of the male flourishing at five years old, and the cow at nine years old, for both expressions have the same meaning.

4. Oxen change their teeth at two years old, not all of them, however, but only like the horse; they do not cast their hoofs when they are lame, but only swell very much about the feet. The milk is good immediately after calving, but the cow has no milk beforehand. The milk which is first formed becomes hard like a stone when it is coagulated; this takes place if it is not mixed with water. They do not produce young before they are a year old, except in some remarkable cases, for some have been known to copulate at four months old. Most of them desire sexual intercourse in the months of April and May. Some, however, are not impregnated before the autumn. When many become pregnant and admit the male, it is a sign of cold and rainy weather. The usual discharges occur in cows as they do in mares, but the quantity is less.

Chapter XXII.

1. Both the horse and mare begin to use sexual intercourse at two years old. Such early cases, however, are rare, and their offspring small and weak; and generally they commence at three years old, and they continue to produce better colts till they are twenty years old. The period of gestation is eleven months; parturition takes place in the twelfth. The male does not impregnate the female in any particular number of days; but at times in one, two, or three, sometimes in more. The ass mounts and impregnates more quickly than the horse; and the act of intercourse is not laborious in horses as it is in oxen. Next to the human subject, the horse in both sexes is the most lascivious of all animals. The sexual intercourse of the younger horses takes place before the usual age according to the goodness and abundance of their food. The horse generally produces but one colt, or sometimes two at the outside. The hemionus has also been known to produce two, but this is considered extraordinary. The horse begins sexual intercourse at thirty months old, so that it can produce proper colts when it has done changing its teeth. Some have been known, they say, to impregnate mares while changing their teeth, unless they were naturally barren.

2. The horse has forty teeth. It sheds its four first teeth at thirty months old, two above and two below. A year afterwards, it sheds four more in the same manner, two above and two below. And again, at the end of the next year, it sheds four more in the same manner. When it is four years and a half old, it sheds no more; and individuals have been known to shed them all at first, and others that have shed them all in the last year. These circumstances are rare, so that it usually happens that the horse is most fit for sexual intercourse at four years and a half old. The older horses are more full of semen, both the males and the females, than younger ones. Horses will copulate both with their dams and with their offspring; and it is thought to be a sign that the herd is complete, when they copulate with their offspring. The Scythians ride upon their pregnant mares when the embryo begins to turn in the uterus, and say that it renders parturition more easy. All other quadrupeds lie down in the act of parturition; wherefore their young are always produced lying on their side; but when the mare feels that the time for parturition is approaching, she stands upright to part with her colt.

3. Horses generally live eighteen or twenty years; some live twenty-five or thirty years; but if they are carefully treated, their life may be extended to fifty years. Thirty years, however, is a very long life for the male, and twenty-five for the female. Some have been known to live forty years. Males live a shorter time than females, on account of the act of sexual intercourse; and those that are brought up separately longer than those which live in herds. Females attain their proper length and height in five years; the males in six. In six more years the fulness of body is acquired, which continues till they are twenty years old. The females attain perfection more rapidly than the males; but in the uterus the males are the more rapidly developed. This is also the case in the human subject. This also takes place in those animals which produce several at a birth.

4. They say that the mule sucks for six months, but the mare will not permit it to come afterwards, because it drags and hurts her. The horse sucks for a longer time. The horse and the mule attain perfection after casting their teeth; and when they have cast them all, it is not easy to know their age. Wherefore they say that, before casting its teeth, the horse has its mark, which it has not afterwards. After the teeth have been changed, the age is usually ascertained by the canine tooth; for that in riding horses is generally worn down, for the bridle rubs against it. In horses which have not been ridden, it is large and not worn. In young horses it is small and sharp.