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 between the _Infundibulum_, in Hens and Frogs, and the Ovary; and yet it cannot be denied that the Eggs are transmitted thro' this into the _Uterus_: And besides _R. de Graef_, and others, have by repeated Observations found that the _Cornua Uteri_ do at certain times after Conception, embrace the _Testes_ on both sides the _Uterus_. They object in the second place the great disproportion between the pretended Eggs in the _Ovary_, and the Aperture of the _Tubæ_ or _Cornua Uteri_, the former being a great deal bigger than the latter: But both _R. de Graef_ and _Malpighius_ have clear'd that Matter, by making appear, that these Bladders in the Ovary are not the _Ova_, but serve to form the _Glandules_ within which the _Ova_ are formed, which break through a small _Papilla_ opening in the _Glandule_, which bears a proportion to the Aperture of the Tube. They object 3, The difficulty to conceive how these Eggs should be impregnated _per semen Maris_, both because there is no Connexion between the _Tubæ_ and the _Ovary_ for its transmission, and for that Dr. _Harvey_ could never discover any thing of it _in Utero_. As to the last, Mr. _Leewenhoeck_ has cleared that difficulty, by the discovery of innumerable _Animalcula Seminis Maris in Cornubus Uteri_, and those living a considerable time after Coition. _Numb._ 174. of the _Transact._ And as to the former, we may either suppose that there is such an Inflation of the _Tubæ_ or _Cornua Uteri tempore Coitionis_, as makes them embrace the _Ovaria_, and such an approach of the _Uterus_ and its _Cornua_, as that I may easily transmit the Seed into the _Ovary_; or else, that the _Ova_ are impregnated by the Animalcles after they descend into the _Uterus_, and not in the _Ovary_; the former seems probable for this Reason, that at least a whole Cluster of Eggs in a Hen will be fecundated by one Tread of the Cock: Now this Fecundation seems to be in the Vitellary, and not in the _Uterus_, as the Eggs pass along from day to day; for it can hardly be supposed that the Animalcles should subsist so long, being scattered loosely in the _Uterus_, as to wait there for many days for the Fecundation of the Eggs as they pass along. The latter Conjecture has this to strengthen it, that the Animalcles are found to live a considerable time in the _Uterus_; and that if they should impregnate the _Ova_ in the Ovary it self, the _Fœtus_ would increase so fast, that the _Ova_ could not pass through the _Tubæ Uteri_, but would either burst the Ovary, or fall down into the Abdomen from the Orifices of the _Tubæ_; and that from hence proceed those extraordinary Conceptions in _Abdomine extra Uterum_. But, 4. Mr. _Leewehoeck_, _Numb._ 147. of the _Transact._ to weaken the third