70 POPULAR SCIENCE MONTHLY. 



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 effec- 

 tive 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 evi- 

 dence 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 Sta- 

 tistical Study of Eminent Men' in the February number of this 

 Monthly, Professor Cattell called attention to the apparent inade- 

 quacy of natural selection to account for the rise and fall of nations. 

 A note in the April number referring to the Harvard statistics also sug- 

 gests the dilemma of the doctrine. The qiiestion 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 produc- 

 tivity. Our returns give support to this claim since the three genera- 

 tions 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 selec- 

 tion 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 environ- 

 ment 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. . 





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