Testibus fœmineis ; for if it were not so, the accidental coming of Animalcles thither could not make them come forward more than in any other part of the Body, since they cannot be formed and nourished without a proper Nidus . But 3. It is acknowledg'd by all, that the Fœtus in Utero , for some considerable time after Conception, has no connexion with the Womb, that it sits wholly loose to it, and is perfectly a little round Egg with the Fœtus in the midst, which sends forth its Umbilical Vessels by degrees, and at last lays hold on the Uterus . Now from hence it seems evident, that the Cicatricula , which is the Fountain of the Animalcles nourishment, does not sprout from the Uterus , but has its Origin elsewhere, and falls in thither as into a fit Soil, from whence it may draw Nutriment for the growth of the Fœtus , else it cannot be easily imagin'd, how it should not have an immediate Connexion with the Uterus from the time of Conception. If you join all these three Considerations together, viz. that an Animalcle cannot come forward without a proper Nidus or Cicatricula ; that there have been frequent Fœtus's extra Uterum ; and that they have no Adhæsion to the Uterus , for a considerable time after Conception, they seem to make it evident, that Animals cannot be form'd ex Animalculis without the Ova in Fœminis . To all these I shall subjoin the Proposal of an Experimentum Crucis , which may seem to determine, whether the Testes Fœmineæ be truly the Ovaria , viz. Open the Abdomen of the Females of some kinds, and cut out these Testicles, and this will determine, whether they be absolutely necessary for the formation of Animals.
There are some Difficulties proposed against this Conjecture, which I think may be easily resolved. Some object the distance between the Tubæ or Cornua Uteri , and the Testicles; but to this is opposed by Swammerdam , and others, the like distance