On the alleged infecundity of females born co-twins with males : with some notes on the average proportion of marriages without issue in general society / by James Y. Simpson.

  • Simpson, James Young, 1811-1870.
Date:
[©1844?]
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Licence: Public Domain Mark

Credit: On the alleged infecundity of females born co-twins with males : with some notes on the average proportion of marriages without issue in general society / by James Y. Simpson. Source: Wellcome Collection.

Provider: This material has been provided by The University of Glasgow Library. The original may be consulted at The University of Glasgow Library.

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    ON THE llEPRODUCTIVE POWEJRS OF FEMALES BORN CO- TWINS WITH MALES AMONG OUR DOMESTIC UNIPAROUS ANIMALS, AND IN THE HUMAN SUBJECT. Mr Jolin Hunter, in an essay read before the Royal Society of London in 1779, and afterwards published both in the Philoso- phical Transactions for that year, and in his work on the Animal Economy, showed that, when among black-cattle the cow brings forth a male and female at the same birth, the male is a perfect bull calf, but the apparent female is almost always imperfect in its sexual organization. Female cattle of this kind, born co-twins with males, have long been distinguished in this country under the name of free-martins. In external appearance and form of body, they usually resemble the ox and spayed heifer more than either the entire male or entire female of the species. They com- monly grow to a larger size than either the bull or the cow, and have horns like those of an ox, and a tone of bellowing similar to his, with the same marked disposition to become fat under the use of nourishing food. In general they do not show any sexual desire for the bull or the bull for them. The defective sexual conformation of free-martin cattle is at- tested, not only by the observation of their sterility during life, but also by the anatomical examination of their reproductive or- gans. Mr Hunter had an opportunity of dissecting several free- martin cows. In all of them the external sexual organs were of the female type—the vuha and os vagince being in general well developed. The vaginal canal, however, was contracted at its up- per part, and the internal female organs (the uterus, Fallopian tubes, and ovaries,) were altogether rudimentary and imperfect in their structure. In some there was an apparent superaddition of male organs (testes and vasa deferentia) probably from a perma- nence of the Wollfian bodies and ducts of the early embryo ; and in one case the ovaries were replaced by bodies having all the ex- ternal characters of male testicles. Mr Hunter's observations have been since corroborated by ad- ditional cases and dissections made by Scarpa,* Gurlt,f and All- natt.^ I have myself had an opportunity of dissecting the sexual parts of two adult and. a third young free martin, killed in the shambles of this city, and have found all of them formed after the anormal and imperfect sexual type pointed out by Mr Hunter. § • Mem. della Societa Iialiana, Tom. ii. p. 846. t l.ehrbuch dcr Pathologisclien Anatomic der Haus-Saugethiere, Bd. ii. s. 18H. Tab. xxi. Fig. 2, 3, and 4. t London Medical Gazette, Vol. xviii. p. 528. § I have described at length the particular anatomical appearances met with in these cases in Dr Todd's Cyclopedia of Anatomy, Vol. i. p. 702 and 70?.