Page:Popular Science Monthly Volume 63.djvu/74

70 a transmission of these variations the fertility of a race must keep up to the racial type and ought to increase. It makes no difference whether the type can change only by sudden extreme variations or by a gradual change of its center of gravity. Of whatever sort the effective variations are, the ones that must needs win in the case of fertility are variations on the plus side. But what we actually find is good evidence of a decrease.

Although such emphatic facts as those reported here have never previously been at hand, the question has been clearly seen. In 'A Statistical Study of Eminent Men' in the February number of this Professor Cattell called attention to the apparent inadequacy of natural selection to account for the rise and fall of nations. A note in the April number referring to the Harvard statistics also suggests the dilemma of the doctrine. The question is there raised whether even if the failure to produce were due to a psychic epidemic of restriction, there should not be on current biological theory a natural selection for certain inheritable mental traits of those individuals who resisted the epidemic and consequently a maintenance of race productivity. Our returns give support to this claim since the three generations involved should give nature a fair amount of time. I shall not, however, make any use at this time of this argument.

The decision of the question is equally clear. In so far as the decrease in the size of families is due to a real decrease in fertility, we have an absolute disproof of racial progress by the perpetuation of the characteristics of those who survive and reproduce. It is a simple question of fact. A comparison of families of different epochs, all of which are known to be unrestricted, would give an indubitable answer, and the argument here must not be a flourish of vague generalities.

So far as present facts go the probability is against natural selection in the case of fertility in man. The contrary hypothesis, that a stock like an individual has a birth, growth, senescence and death; that, apart from the onslaughts of rivals or the privations of a hard environment or the suicide of universal debauchery, races die a natural death of old age, lends itself very well to the interpretation of human history and perhaps to the history of animal forms as well. It leaves the causation of this race life and death as a mystery. But a mystery is less objectionable than a contradiction.