The periodical maturation and extrusion of ova, independently of coitus, in mammalia and man, proved to be the primary condition to their propagation / Translated from the German by Henry Smith.

  • Bischoff, Th. Ludw. Wilh. (Theodor Ludwig Wilhelm), 1807-1882
Date:
1845
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Licence: Public Domain Mark

Credit: The periodical maturation and extrusion of ova, independently of coitus, in mammalia and man, proved to be the primary condition to their propagation / Translated from the German by Henry Smith. Source: Wellcome Collection.

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    “ heat/* from which the ova have escaped without the act of copulation having taken place. A short time since I examined a rabbit six or eight hours after coitus, and found that the ova had not as yet quitted the Graafian vesicles, which were much swollen. In addition to these, however, there were corpora lutea of a considerable size in both ovaries, which could not be the effect of a previous littering, as they were much too large for that, and the animal had also been kept alone for several weeks previously. I regard these likewise, therefore, as corpora lutea of a “period of heat” which had passed over without copulation. From all that I have stated, then, it is quite certain, that at the period of “ heat,” and even when no act of copulation takes place, the ova of mammalia are extruded from the ovary, and enter the fallopian tube, but that they there prove abortive : corpora lutea, however, are formed upon the ovary as though coitus and impregnation had been effected. As a counterpart to these observations, which prove the maturation and extrusion of ova independently of the seminal fluid of the male, I will adduce another fact, which proves the same on the other hand for the semen. On the 6th of March, 1844, I examined a bitch, not knowing when the animal had received the male for the first time, but being certain that coitus had taken place the day before. The left ovary exhibited three corpora lutea, and in the centre of the oviduct I found the three ova quite normal in condition. The right ovary, on the contrary, was very small, and did not exhibit either a swollen or an opened Graafian vesicle, or corpus luteum, and of course there was no ovum in the tube. I found spermatozoa, however, in the uterus and oviduct, not only as high as the ovary, but upon it. This proves positively that no especial design is in operation here. According to the general mode of considering organic phenomena, which always presupposes a precise design, one would have expected that when no ovum was to be fecundated the seminal fluid would not have reached the part. But it had pursued its customary course un¬ interrupted, just as the ovum takes its own quite independently of the semen. There is no attraction, no polarity, or such like force, in operation here, such as we are so ready to apply to the supposed explanation of certain natural phenomena. Ovum and seminal fluid are altogether independent products of older organisms. Their meeting, and the con¬ sequent fecundation of the ovum, although necessary for the maintenance of the species, are in themselves quite accidental occurrences, frequent instances of which are so clearly evident in organic nature. If, then, the foregoing observations prove, with respect to mammalia, that their generation and propagation are brought about primo loco by the spontaneous periodical formation and maturation of ova, and not by