Page:Popular Science Monthly Volume 30.djvu/754

730 well be omitted from an address such as this purports to be, and it may well engage a little attention before I bring these remarks to a close.

And first a few words in regard to the comparative anatomy and physiology of the male and female brain.

The skull of the male of the human species is of greater capacity than that of the female, and it is a singular fact that the difference in favor of the male increases with civilization. Thus in savage nations as the Australians and the negroes of Africa, the skulls of men and women are much more alike in size than they are in Europeans. It would appear from this fact, either that women from some cause or other have not availed themselves of the advantages of civilization as factors in brain-development to the same extent as man has; or that among savages there is not that dissimilarity in mental work that is found among civilized nations, and that hence there is not the same necessity for a difference in brain-development. For it naturally follows that, in the normal skull, there is a correspondence between its size and that of the organ contained within it.

Many observations have shown that the average male brain weighs a little over forty-nine ounces, while the average female brain is a little over forty-four ounces, or about five ounces less. The proportion existing between the two is therefore as 100: 90.

This apparently makes a good showing for man, but when we look at the matter in another, and possibly a more correct light, the advantage is rather the other way; for, relatively to the weight of the body in the two sexes, the difference, what there is, is in favor of woman. The body of the female is shorter and weighs less than that of the male. Thus, in man the weight of the brain to that of the body has been found to be an average of 1: 36-50, while in woman it is as 1: 36-46, a difference of -04 in her favor. I have said that possibly this may be a more correct way of determining the size of the brain than by absolute measurements without regard to the size of the body. The doubt arises from the fact that we do not know that very thin persons, in whom of course, other things being equal, the brain would be relatively larger, are more remarkable for mental vigor than are very stout ones, in whom the relative size of the brain would be less. Such being the case, it is difficult to believe that the proportionate size of the brain to that of the body has any important influence as a factor in the production of mind. It is the absolute rather than the relative amount of gray matter that is to be considered in determining the brain-power. It must, however, be borne in mind that the quantity of gray matter can not always be positively affirmed from a determination of the size of the brain, though in general it can. A person, for instance, may have a large head and a large brain and the layer of cortical substance be very thin; and another person with a smaller brain may have the cortex so thick as to more than compensate for its