"It is evident also from the generation of the chick, that whatever the source of its life or the vegetative first cause of it may be, this had a prior existence in the heart. Wherefore, if the said first cause be itself the soul of the chick, it stands proved likewise that this had a prior existence in the leaping point and the blood; seeing that we observe therein motion and sensation; for it moves and leaps like an animal. If, then, there exist in the leaping point the soul, which (as I have taught in my account) constructs for itself the rest of the body, nourishes and increases it, certainly from the heart as from a fount the soul flows out[287] into the entire body. "So, likewise, if the egg be prolific because there is a soul in it, or (as Aristotle would have it) the vegetative part of the soul, it is clearly proved that the leaping point, in other words the generative part endowed with soul, springs from the soul of the egg, for nothing is the author of itself, and that the soul is transferred from the egg to the leaping point, next to the heart, and then to the chick."[288] In still another chapter of his treatise On Generation Harvey says:-- "Nor does the blood deserve to be called the original[289] part and the principal part, merely because in it and by it motion and pulsation are originated, but also because in the blood the psychical heat first comes into existence, the vital spirits are generated, and the soul itself inheres. For wherever the immediate and principal instrument of the vegetative faculty is first found, there probably the soul also is first present and takes its origin thence; since the soul is inseparable from the spirits and the innate heat....[290] "The life then inheres in the blood (as we read also in Holy Writ),[291] because therein the life and the soul are manifest first and fail last....[292] "It stands clearly proved that the blood is a generative part, the source of life, the first to live and the last to die, the primary seat of the soul; that in the blood, as in its source, the heat first and chiefly abounds and flourishes; and that by and from the blood all the other parts of the whole body are fostered and obtain their life by means of the influx of heat. Indeed, the heat which accompanies the blood floods, fosters, and preserves the entire body, as I have demonstrated already in my book on the motion of the blood."[293] Harvey's proof that the blood is "the first to live and the last to die," we have scanned already in an earlier chapter of this paper. In the next chapter of his treatise On Generation he says:-- "No heat is to be found, either innate or inflowing, other than the blood, to be the soul's immediate instrument."[294]