312 



DR MATTHEWS DUNCAN ON THE 



TABLE XXV. — Showing the Effect of the Postponement of the Marriages 

 of the Peeresses on their Prolificness. (Sadler.) 



Period of Marriage. 



Number 

 of Marriages. 



Number 

 of Children. 



Births to each 

 Marriage. 



From 12 to 15, . . . 

 „ 16 to 19, . . . 

 „ 20 to 23, . . . 



„ 24 to 27, . . . 



32 

 172 

 198 



86 



141 



797 



1033 



467 



440 

 4-63 

 521 

 5-43 



To this Table of Sadler's many objections may be made, such as the paucity 

 and insecurity of the data, as also their deficiency, the highest age of marriage 

 included in them being only 27, and all notice of the important element of the 

 duration of marriage being omitted. 



Sadler not only erred in supposing he had demonstrated that late marriages 

 are more prolific than early. He was ignorant also that a larger proportion of 

 the elder than of the younger wives bears no children at all, and that an elderly 

 Avoman continues fertile a shorter time than a younger, counting, in both cases, 

 only up to periods within the child-bearing portion of life. 



It is a natural, and I believe a true, notion, that twin-bearing should be a 

 sign of intense fertility in woman, as the number of a litter certainly is in 

 bitches, and other inferior animals. In confirmation of this notion, and of the 

 law of intensity of fertility now demonstrated, we find that women are more likely 

 to bear twins the older they are. This subject is capable of some interesting 

 developments ; but, as I have already elsewhere* entered upon them, I shall add 

 no more in this place, merely remarking, that they were completed at a time 

 when the law of intensity of fertility was only guessed at, and, therefore, Avhen 

 the explanation of the great twin-bearing of old women was not known to me. 



In like manner, it is natural to suppose that the length and weight of children 

 should go with intensity of fertility. But my researehesf seem to show that this 

 is not the case, but that length and weight of children go with the intensity of 

 fecundity, or likelihood of bearing children, according to age. Professor PTecker, 

 of Munich, has, however, elaborately shown that my conclusions on this head do 

 not agree with those derived from his larger data.t Mine are based on 2087 

 observations only, and I am willing, in the meantime, to hold it as subjudice. 

 whether his or my conclusions are to be received. His do appear to me the more 



* Edinburgh Medical Journal for March and April 1865. f Ibid., December 1864. 



i Monatsschrift fur Geburtskunde und Fiauenkranklieiten, November 1865. 



