We are now in a condition to judge of the value of Harvey's experiments and observations. There is great appearance this anatomist did not make use of a microscope, which in fact was not brought to perfection in his days, or he would not have asserted there was no difference between the cicatrice of an impregnated and an unimpregnated egg; he would not have said the seed of the male produced no alteration in the egg, especially in the cicatrice; he would not have affirmed that nothing was perceptible till the third day, that the animated speck was the first that appeared, and into which the white speck was changed. He would have seen that the white speck was a ball which contained the whole apparatus of generation, and that every part of the foetus are there from the moment the hen has connection with the cock. He would also have learnt, that without this connection it contains only an unshapen mass, which could never become animated, because in fact it is not organized like an animal, and because it is only when this mass, which we must look upon as an assemblage of the organic particles of the female semen, is penetrated by the organic particles of the male semen, that there results from it an animal, which is formed at the moment, but whose motion is imperceptible till the end of forty hours after: he would not have asserted that the heart is first formed, and that the other parts are joined to it by a juxta-position, since it is evident from Malpighius's observations, that the outlines of every part are all immediately formed, but only appear in proportion as they dilate; on the whole, if he had seen what Malpighius saw, he would not have affirmed that no impression of the male seed remained in the eggs, and that it was only by contagion that they are fecundated, &c. It is also just to remark, that what Harvey has said on the parts of the generation of a cock is not exact; he asserts that the cock has no genital member, and that there is no intromission; nevertheless it is certain that this animal, instead of one has two, and that they both act at the same time, and which action is a very strong compression, if not a true copulation;[I] and it is by this double organ that the cock emits the seminal liquor into the matrix of the hen. [I] See Reyn. Graaf, page 242. Let us now compare the experiments made by Harvey on hinds with those of De Graaf on doe rabbits; we shall find that although De Graaf supposes, with Harvey, that all animals proceed from eggs, yet there is a great difference in the mode which these two anatomists have observed in the first steps of formation, or rather expansion, of the foetuses of viviparous animals.