Ovulation and degeneration of ova in the rabbit / by Walter Heape ; (communicated by Adam Sedgwick).

  • Heape, Walter, 1855-1929.
Date:
1905
Catalogue details

Licence: In copyright

Credit: Ovulation and degeneration of ova in the rabbit / by Walter Heape ; (communicated by Adam Sedgwick). Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    activity of the whole generative system is not in the ovary, that organ is at least essential to the normal functions of the I'emainder of the system. In the same way excision of the generative glands affects, for instance, the growth of horns in the male, and exercises influence in various ways on other organa of the body of both sexes. Thus these organs are probably essential to the normal development of sexual characteristics. There would seem to be little room for doubt that this is the case. But in all animals which liave a special breeding season, the ovary has a quiescent period, so. far as the development of the ova are concerned, varying in accordance with the length of the interbreeding seasons. Tor some time before the advent of the sexual season, however, with the probable exception of bats, the ovary exhibits activity, and is obviously engaged in transjuitting nutriment to the ova, which now begin to develop. The commencement of this active season is marked by the increased vascularity of the gland. The fact that this ovarian activity precedes the sexual season is not unfavourable to the view that it exercises influence on the latter. It must be recollected, however, that monkeys, although they menstruate regularly each month throughout the year, have a subscribed breeding season, and their regular menstrual function goes on during the time when the ovary is quiescent. Moreover, as ovulation in the bat may take place many months after the sexual season is over, and the bat’s ovary is certainly quiescent during those intervening months, it may be expected that the sexual season in bats occurs in the absence of ovarian activity. Finally, it is quite clear that ovulation and prooestrum are not necessarily coincident in many animals. If these facts are true, it does not seem possible to accept the view that the stimulus which induces procestrum and oestrus has its. origin in the ovary. There is another point to be considered, namely, that the advent of sexual activity may be hastened or delayed or, perhaps, prevented altogether; the severity of procestrum and oestrus augmented or reduced; and the ratio of fertility influenced, by climatin conditions and food. Similar conditions obtain and similar results follow in the male. Generative Ferment and “ Gonadin”—My belief is that the stimulus which primarily induces such, activity is of extraneous origin.; that it is due to.a change in the constitution of the blood, brought about by climatic influences and food, which from the nature of its growth would seem to be always specially nutritious at this season; that it results in increased vitality throughout the body—clearly evidenced by the growth of horns, wattles, and other excrescences, by the growth of hair and plumage, and the accession of brilliant colouring to such epidermic growths or to the skin itself—and similarly affects the generative system.