before and after Incubation: And R. de Graef, and others, having upon many Observations concluded, that the Testes Fœminei were the Ovaries of Females, and consequently that all Animals were ex ovo; they began from hence to infer, that the Rudiments of each Animal were originally in the respective Females, and that the Male contributed only to give a new Ferment to the Mass of the Blood and Spirits, by which means a spirituous Liquor (which the Blood in its ordinary Ferment could not produce) did insinuate it self into the same Ducts and Pores of the Rudiments of those Animals, which were in greatest forwardness in the Ovary, and so extend and enlarge all their Parts, and at last bring them to perfection, as Mr. Perrault does ingeniously discourse in the third Part of his Essais de Physique; till now at last Leowenhoek has discover'd an infinite number of Animalcula in semine marium of all kinds, which has made him condemn the former Opinions about the Propagation of all Animals ex Ovo.
Now upon comparing the Observations and Discoveries which have been made with one another, these three things seem to me very probable. 1. That Animals are ex Animalculo. 2. That these Animalcles are originally in semine Marium & non in Fœminis. 3. That they can never come forward, nor be formed into Animals of the respective kind, without the Ova in Fœminis.
The first of these seems probable from these three Observations. 1. That some such thing has been so often observ'd by Malpighius, in the Cicatricula of an Egg before Incubation, as the Rudiments of an Animal in the shape of a Tadpole, as may be seen in his first, and in his repeated Observations de formatione Pulli in Ovo. 2. The sudden appearance and displaying of all the Parts after Incubation, makes it probable, that they are not then actually formed out of a fluid, but that the Stamina of them have been formerly there existent, and are now expanded. The