Page:The Works of William Harvey (part 1 of 2).djvu/463

 the prime and principal fertilizer, whence all mediate causes receive the fecundity imparted. For example, the chick is derived from the punctum saliens in the egg, not only as re- gards the body, but also, and this especially, as respects the life (anima) : the punctum saliens, or heart, is derived from the egg, the egg from the hen, and the hen has her fecundity from the cock.

Another condition of the prime efficient is discovered from the work achieved, viz., the chick, because that is the prime efficient in which the reason of the effect is principally dis- played. But since every generative efficient engenders ano- ther like itself, and the offspring is of a mixed nature, the prime efficient must also be a certain mixed something.

Now, I maintain that the offspring is of a mixed nature, in- asmuch as a mixture of both parents appears plainly in it, in the form and lineaments, and each particular part of its body, in its colour, mother-marks, disposition to diseases, and other accidents. In mental constitution, also, and its manifesta- tions, such as manners, docility, voice, and gait, a similar tem- perament is discoverable. Tor as we say of a certain mixture, that it is composed of elements, because their qualities or vir- tues, such as heat, cold, dryness, and moisture, are there dis- covered associated in a certain similar compound body, so, in like manner, the work of the father and mother is to be discerned both in the body and mental character of the offspring, and in all else that follows or accompanies temperament. In the mule, for instance, the body and disposition, the temper and voice, of both parents (of the horse and the ass, e. g.} are mingled ; and so, also, in the hybrid between the pheasant and the fowl, in that between the wolf and the dog, &c., corresponding traits are conspicuous.

When, therefore, the chick shows his resemblance to both parents, and is a mixed effect, the primary genital cause (which it resembles) must needs be mixed. Wherefore that which fashions the chick in the egg is of a mixed nature, a certain something mixed or compounded, and the work of both pa- rents. And if any kind of contagion, engendered under the in- fluence of sexual intercourse, in which the male and female min- gle and form but one body, either originates or remains in t)ie body of the female, that, too, must be of a mixed nature or