Page:The Works of William Harvey (part 1 of 2).djvu/507

 EXERCISE THE FIFTY-FIFTH.

Of the order of the parts according to Aristotle.

The following appear to be Aristotle's views of the order of generation : * " When conception takes place, the germ com- ports itself like a seed sown in the ground. For seeds likewise contain a first principle, which, existing in the beginning in po- tentia, by and by when it manifests itself, sends forth a stem and a root, by which aliment is taken up ; for increase is indis- pensable. And so in a conception, in which all the parts of the body inhere in potentia, and the first principle exists in a state of special activity."

This principle in the egg the body analogous to the seed of a vegetable we have called with Fabricius the spot or cica- tricula, and have spoken of it as a very primary part of the egg, as that in which all the other parts inhere in potentia, and from whence each in its order afterwards arises. In this spot, in fact, is contained that whatever it may be by which the egg is made productive ; and here is the first action of the formative faculty, the first effect of the vegetative heat revealed.

This spot, as we have said, dilates from the very commence- ment of the incubation, and expands in circles, in the centre of which a minute white speck is displayed, like the shining point in the pupil of the eye ; and here anon is discovered the punc- tum saliens rubrum, with the ramifications of the sanguiferous vessels, and this as soon as the fluid, which we have called the colliquament, has been produced.

" Wherefore," adds Aristotle, 2 " the heart is the first part perceived in fact ; and this is in conformity not only with sense, but also with reason. For as that which is engendered is al- ready disjunct and severed from both parents, and ought to rule and regulate itself like a son who comes of age and has his separate establishment, it must therefore possess a principle, an intrinsic principle, by which the order of the members may

1 Uc Gen. Anim. lib. ii, cap. 4. 2 Ibid.