Page:Popular Science Monthly Volume 62.djvu/253

Rh valuable it may be in other respects, has no decisive bearing on the question he undertook to answer, and can have no very damaging effect on the writers he attacks. But there is considerable interest in driving the point of the discussion still further home.

It may be agreed that since differences in size are probably affected by the influences of life and death to a considerable extent, and perhaps unequally eliminated in the two sexes, they do not form a reliable guide to the sexual incidence of variations. But, it may be argued, this cannot affect measurements made at birth, and we must therefore accept the validity of those of Professor Pearson's measurements which concern the infant at birth. Here, however, we encounter a fact which is of the first importance in its bearing on our subject: the elimination of variations in size has already begun at birth, and there is reason to suppose that that elimination unequally affects males and females. This was duly allowed for in 'Man and Woman,' but there is no hint of it throughout Professor Pearson's long paper. He does not dispute this influence, nor does he realize that until he has disputed it his conclusions can not be brought to bear against mine. Professor Pearson's earlier statistical excursions into the biological field were chiefly concerned with crabs; in passing from crabs to human beings he failed to allow for the fact that human beings do not come into the world under the same conditions. I make no large claim for superior insight in this matter; it was probably a question of training; I was practically familiar with the phenomena of childbirth; he was not. But his ignorance has profoundly affected the validity of his cherished criterion of sex variability, in so far as it is used against his predecessors in this field.

Every child who is born into the world undergoes a severe ordeal, due largely to the limited elasticity of the bony pelvic ring through which it has to pass. Probably as a result of this, a certain proportion perish as they enter the world or very shortly after. Among the number thus eliminated there appears to be a very considerable proportion of the largest infants. Doubtless because male infants tend to be larger than female infants, males suffer most at and shortly after birth. This appears to be the rule everywhere.

So far as I am aware, the first attempt to explain this matter scientifically was made in 1786 by an English doctor named Clarke, physician to the Lying-in Hospital at Dublin. By weighing and