Page:The Works of William Harvey (part 1 of 2).djvu/379

 is extant. Nor is it more credible that the vital principle of the egg and chick can be identical, if the vital principle be con- servative of that only to which it belongs ; but the egg and the chick are different things, and manifest dissimilar and even opposite vital acts, in so much so that one appears to be pro- duced by the destruction of the other. Or should we perchance maintain that the same principle and cause of life inheres in both, in the pullet half fashioned, to wit, and the egg half con- sumed, as if it were one and a simple act of the same body; or as if from parts producing one natural body, one soul or Altai principle also arose, which was all in all, as is commonly said, and all in each particular part ? Just as with leaves and fruit conspicuous on the stem of a tree, wherever a division is made we still say that the principle or first cause of the slip and of the whole tree is the same ; the leaves and the fruit are, as it were, the form and end, the trunk of the tree the beginning. So too in a line, wherever a division is made, this will become the end or boundary of the part behind it, the commencement of the part before it. And the samfe thing is seen to obtain in respect of quality and motion, that is to say, in every kind of transmutation and generation.

So much at this time upon these topics, which will by and by engage us at greater length, when we come to speak of the nature of the living principle of the embryos of animals in general; of its being; of its accession in respect of the how and the when; and how it is all in all, and all in each particular part, the same and yet different. Points which we shall deter- mine from numerous observations.

EXERCISE THE TWENTY-SEVENTH.

The egg is not the product of the uterus, but of the vital principle.

" As we have said," says Fabricius,i " that the action of the stomach was to convert the food into chyle, and the action of the

1 Op. cit. p. 8.