this time, no one is ever attacked by the crocodile; on the eighth day, however, after the sixth hour, these beasts resume all their former ferocity. CHAP. 72. (47.)—SHEEP, AND THEIR PROPAGATION.[1971] Many thanks, too, do we owe to the sheep, both for appeasing the gods, and for giving us the use of its fleece. As oxen cultivate the fields which yield food for man, so to sheep are we indebted for the defence of our bodies. The generative power lasts in both sexes from the second to the ninth year, sometimes to the tenth.[1972] The lambs produced at the first birth are but small. The season for coupling, in all of them, is from the setting of Arcturus, that is to say, the third day before the ides of May,[1973] to the setting of Aquila, the tenth day before the calends of August.[1974] The period of gestation is one hundred and fifty days. The lambs that are produced after this time are feeble; the ancients called those that were born after it, cordi.[1975] Many persons prefer the lambs that are born in the winter to those of the spring, because it is of much more consequence that they should have gained strength before the summer solstice than before the winter one; consequently, the sheep is the only animal that is benefitted by being born in the middle of winter. It is the nature of the ram to reject the young and prefer the old ones, and he himself is more serviceable when old,[1976] and when deprived of his horns.[1977] He is also rendered less violent by having one horn pierced towards the ear. If the right testicle is tied up, the ram will generate females, and if the left, males.[1978] The noise of thunder produces abortion in sheep, if they are left alone; to prevent such accidents, they are brought together into flocks, that they may be rendered less timid by being in company. When the north-east wind blows, males are said to be conceived; and when the south wind, females. In this kind of animal, the mouth of the ram is especially looked to, for whatever may be the colour of the veins under the tongue, the wool of the young one will be of a similar colour.[1979] If these veins are many in number, it will be mottled. Any change, too, in their water or drink, will render them mottled.[1980] There are two principal kinds of sheep, the covered[1981] and the colonic,[1982] or common sheep; the former is the more tender animal, but the latter is more nice about its pastures, for the covered sheep will feed on brambles even. The best coverings for sheep are brought from Arabia.[1983] CHAP. 73. (43.)—THE DIFFERENT KINDS OF WOOL, AND THEIR COLOURS.[1984]