Chapter XXI.

What Time is Required to Shape the Parts of Animals in the Womb.

Empedocles believes, that the joints of men begin to be formed from the thirty-sixth day, and their shape is completed in the nine and fortieth. Asclepiades, that male embryos, by reason of a greater natural heat, have their joints begun to be formed in the twenty-sixth day - many even sooner - and that they are completed in all their parts on the fiftieth day; the parts of the females are articulated in two months, but by the defect of heat are not consummated till the fourth; but the members of brutes are completed at various times, according to the commixture of the elements of which they consist.