It is a curious fact that the relative number of males and females born is nearly equal, there being only a small majority in favour of the former, in the proportion of 21 to 20; in consequence of which both sexes are equal at the age of 14, since more male children are still-born, or die in infancy, than females, owing, as _Dr. Clarke_[407] has supposed, to the relative size of the head, being greater in the former. _Hufeland_[408] has collected the relative number of the two sexes in all parts of the world, and has found them every where the same. “It seems very singular,” says Sir _Gilbert Blane_,[409] “and at the same time most admirable in the institution of Nature, that this relative number of the sexes should be maintained, though the primordial germs are mixed in different proportions in the ovaria of different females; for it is well known that many women produce such a number of children in succession, of the same sex, as is utterly irreconcileable with the laws of blind chance, another word for mathematical necessity.” The reader will also derive much pleasure by the perusal of a memoir[410] upon this subject by _Dr. Arbuthnot_, entitled “_An Argument for Divine Providence, taken from the constant regularity observed in the birth of both Sexes_” from which the learned author deduces as a scholium, that polygamy is contrary to the law of Nature and justice, and to the propagation of the human species. Q. 9. _Is Super-fœtation possible, and under what circumstances, and at what period of Gestation can a second conception take place?_ The term _Super-fœtation_ implies that a second impregnation may take place, whilst a child is in utero. There are perhaps few questions relating to the subject of conception, that have given origin to more rigorous controversy; and indeed its important judicial bearings render it a subject of greater interest than it could ever have become intrinsically as a mere object of abstract speculation. Let us, for the sake of illustration, suppose the following case:—A woman loses her husband suddenly, _tenant in tail male_, a month after marriage, and at a little more than eight months after his decease she is delivered of a perfect female child, and at nine months, she declares that she is delivered of another infant, which is a male. The heir at law, who has entered, contests the fact of this latter birth; the question therefore to be determined is, whether such an event is compatible with the known laws of utero-gestation.