We should be perfectly convinced, that eggs are only destined by Nature to serve as a matrix in animals who have not that viscera, by those females producing eggs independant of the male. In the same manner as the matrix exists in viviparous animals, as a part appertaining to the female sex, hens, which have no matrix, have eggs in their room, which are successively produced of themselves, and necessarily exist in the female independently of any communication with the male. To pretend that the foetus is pre-existing in the eggs, and that these eggs are contained, _ad infinitum_, within each other, is nearly the same as to pretend that the foetus, is pre-existing in the matrix, and that the matrix of the first female inclosed all that ever were or will be produced.
Anatomists have taken the word _egg_ in several acceptations and meanings. When Harvey took for his motto, _Omnia ex ovo_, he understood by the word egg, as applied to viviparous animals, the membrane which includes the foetus and all its appendages: he thought, he perceived this egg, or membrane, form immediately after the copulation of the male and the female. But this egg does not proceed from the ovium of the female; and he has even maintained, that he did not remark the least alteration in this testicle, &c. We perceive there is here nothing like what is commonly understood by the word egg unless the figure of the bag may be supposed to have some resemblance thereto. Harvey, who dissected so many viviparous females, did not, he says, ever perceive any alteration in the ovaria; he looked on them even as small glands, perfectly useless to general ion,[Y] although they undergo very remarkable changes and alterations in them, since we may perceive in cows the glandular bodies grow from the size of a millet seed to that of a cherry. This great anatomist was led into this error by the smallness of the glandular bodies in the species of deer, to which he principally paid his attention. C. Peyerus, who also made many experiments on them, says, "Exigui quidem sunt damarum testiculi, sed post coitum foecundum, in alterutro eorum, papilla, sive tuberculum fibrosum, semper succrescit; scrofis autem prægnantibus tanta accidit testiculorum mutatio, ut mediocrem quoque attentionem fugere nequeat."[Z] This author imagines, with some reason, that the minuteness of the testicles of does, is the cause of Harvey's not having remarked the alterations; but he is wrong in advancing that the alterations he had remarked, and which had escaped Harvey's notice, did not happen till after impregnation.