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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    cient number of such cases for forming some just conclusions upon this subject. Before, however, bringing forwards the results derivable from these collected cases, as bearing upon the question of the fecundity or sterility of human females born under the circumstances in question, I may, in the first place, mention that instances of twins in the human subject, of whom one child is male and the other fe- male, seem not to be at all rare in their occurrence, though the con- trary position is generally bcliewd, and as we have seen was as- sumed by Home, and made by him at one and the same time a de- duction from, and an argument in favour of the particular theory which he held, in respect to sexual development. In proof of this statement, I have analyzed the records of all the labours that oc- curred in the Edinburgh General Lying-in Hospital from 1823 to. 1836, both years included, as well as the published returns of all the cases occurring in the Dublin Lying-in Hospital from 1787 to 1793, as given by Dr Clark, and from 1826 to 1833, as given, by Dr Collins,* as also those occurring in the London Maternity Charity from 1828 to ]840,f wiiich are the only returns that I am aware of in which the average number of twin labours and the sexes of the different co-twins have been noted. The three fol- lowing tables have been constructed from these reports. The first of them shows the average number of twin labours as they occur- red in these institutions respectively ; the second presents the sexes of the different pairs of twins as they occurred in each ; and the third illustrates the proportion in which the different scxed co- twins were to the general number of labours. J. Total number and proportion of twin-labours. Total number Number of Proportion of of Labours. Twin Labours. Twin Labours. Edinburgh Hospital, . 28H8 4() | in Gti Dublin Hospital, (Clark,) )0-387 J84 1 ... 5f; Dublin Hospital, (Collins,) 16-414 240 1 ... London Maternity Charity, 2y-'189 318 1 93 59-178 788 1 in 75 II.—Sexes of the different co-twins in the above 788 cases. Two Two Male and Tot. number males. females. female. of twins. Edmburgh Hospital, . 16 17 ]3 4fj Dublin Hospital, (Clark) . 47 66 71 jfii ^ ,, , „ . ^^^^ Dublin Hospital, (Colhns) . 73 67 100 London INlaternity Charity, . 93 111 114 318 _ . . , 229 261 298 788 III. Proportion in which the different sexed co-twins occurred to the whole 59.178 cases of labour : Male and female twins once in every 199 labours. Two female twins once in every 226 labours. Two male twins orce in every 258 labours. • Dr Collins's Practical Treatise on Midwifery, 1836, table beginning p 331 + Dr Ramsboth..m's Pnncples and Practice of Obstctiic Medkine and Surety p. 021, foot-note. »^'15«'>»