By comparing these observations with those of Harvey, we shall easily perceive that the principal circumstances have escaped the latter; and although there are many errors in the reasoning and experiments of De Graaf, nevertheless this anatomist, as well as Malpighius, has made better observations than Harvey. They agree in the principal points, and are both contrary to Harvey; the latter had never seen the alterations which happen to the ovary; he did not see the small globules in the matrix which contain the apparatus of generation, and which De Graaf calls eggs. He had not even a supposition that the fœtus existed in this egg; and though his experiments gave us nearly an exact account of what occurs during the growth of the fœtus, they give us no information either of the moment of fecundation or of the first development. Schrader, a Dutch physician, who held Harvey in great veneration, owns that we must not put too great a reliance in that anatomist in many things, and especially on what he says of the fecundative moment, for the chicken in fact is in the egg before incubation, and that Joseph de Aromatarius was the first who observed it.[J] Although Harvey pretended that every animal proceeds from an egg, he did not imagine that the testicles of females contained these eggs, and has only repeated what Aristotle has said on this subject. The first who speaks of having discovered eggs in female ovaries is Steno, who says, in dissecting a female sea-dog he saw eggs in the testicles, although that animal is viviparous; and he adds, that the testicles of women are analogous to the ovaries of oviparous animals, whether the eggs fall in any manner into the matrix, or whether there only falls the matter they contain. Although Steno is the first who discovered these pretended eggs, De Graaf claims the merit to himself, and Swammerdam has disputed it with him, insisting that Van Horn had perceived these eggs before De Graaf. It is true this last writer stands charged with asserting many things experience has found to be false. He pretended that a judgment might be formed of the number of fœtuses contained in the matrix by the number of cicatrices, or empty follicules, in the ovary, which is not true, as we may see by the observations of Verrheyen,[K] and by those of M. Mery,[L] and by some of De Graaf's own observations, where he found fewer eggs in the matrix than cicatrices in the ovaries. Besides, we shall make it appear that what he says concerning the separation of the eggs, and the manner in which they descend into the matrix, is not exact; that no eggs exist in the female testicles; that what is seen in the matrix is not an egg; and that nothing can be worse founded than the systems endeavoured to be established on the observations of this famous anatomist.
[J] See Observ. Justi Schraderi, Amst. 1674.
[K] Vol. I. chap. iii. Brussels edit. 1710.
[L] Hist. of the Academ. 1704.
This pretended discovery of eggs in the testicles of females attracted the attention of most anatomists; they, however, only met with small bladders in the testicles of female viviparous animals, these they did not hesitate to look on as real eggs: they therefore gave the name of ovaries to the testicles, and called the vesicles eggs, They also said, with De Graaf, that there are eggs of different sizes in the ovarium; that the largest in the ovarium of women was not above the size of a small pea; that they were very small in the young, but increased with age and intercourse with men; that twenty might be counted in each ovarium; that these eggs are fecundated in the ovarium by the spirited part of the seminal liquor of the male; that afterwards they loosen and fall into the matrix, where the fœtus is formed, from the internal substance of the egg and the placenta of the external matter; that the glandular substance, which does not exist in the ovarium till after a fruitful copulation, serves to compress the egg, and make it quit the ovarium, &c. But Malpighius having examined things more minutely, detected many of their errors before they were even received; yet most physicians adopted the sentiments of De Graaf, without any attention to the observations of Malpighius; which, notwithstanding, are very important, and to which his scholar Valisnieri has given a great deal of weight.
Malpighius and Valisnieri, of all naturalists, speak with the greatest foundation on the subject of generation. We shall therefore give an account of their experiments and remarks, to which we cannot pay too much attention.
Malpighius having examined a great number of the testicles of cows and other female animals, affirms that he found vesicles of different sizes in the testicles of all of them, whether young or adults; these vesicles are inclosed by a thick membrane, in the inner parts of which there are blood-vessels, filled with a kind of lymph, or liquor, which hardens by the heat of the fire like the white of an egg.
In time a firm yellow body grows which adheres to the testicles. It is prominent and increases to the size of a cherry, occupying the greatest part of the ovarium. The body is composed of many little angular tubes, and its position is irregular; it is covered with a coat, or membrane, spread over with nerves and blood-vessels. The appearance and form of this yellow body are not always the same, but vary according to time. When not above the size of a millet seed, it is nearly globular, and if divided appears composed of a kind of variegated net-work. Very often an external covering is observed, composed of the same substance as the yellow body, around the vesicles of the ovarium.
When the yellow body is become nearly of the size of a pea, it is the shape of a pear, in which is a small cavity filled with liquor; as is also the case when grown to the size of a cherry. In some of these yellow substances, when increased to their full maturity, Malpighius says, a small egg, with its appendages, not bigger than a millet seed, may be seen near the centre; when they have cast out their eggs they are empty, resemble a cavernous passage, and the cavities which inclose them are about the size of peas. He thinks this yellow and glandular substance nature produces to preserve the egg, and assist it in leaving the testicles, and perhaps to contribute towards the generation of the egg itself; consequently, he says, the vesicles, which are always observed in the ovary, and which are of different sizes, are not real eggs that may be fecundated, but only serve for the production of the yellow body where the egg is to be formed. On the whole, although these yellow substances are not found at all times in all testicles, we nevertheless always find the first traces of them, and Malpighius having seen the marks of them in young heifers, cows that were with calf, and in pregnant women, he reasonably concludes that this yellow and glandular substance is not, as De Graaf has supposed, the effect of fecundation, but what produces the infecund eggs, which leave the ovary without any communication with the male, as well as to those which leave it after communication. When the latter falls into the tubes of the matrix, all the rest is performed as De Graaf has described.
These observations of Malpighius shew that the testicles of females are not real ovaries, as most anatomists believe; that the vesicles they contain are not eggs; that these vesicles never fall into the matrix; and that the testicles, like those of the male, are kinds of reservoirs, containing a liquor which must be looked upon as an imperfect seed of the female, that is perfected in the yellow glandular body which fills the internal cavity, and is shed when the glandular substance has acquired its full maturity. But before we decide on this important point, we must relate the observations of Valisnieri; and we shall perceive that, though Malpighius and Valisnieri have made good observations, they have not carried them far enough, nor drawn those consequences from them which their observations might naturally have produced, because they were both prejudiced for the system of eggs, and of the fœtus pre-existing therein.