222 SPECULATIVE SCIENCE 



the progress of a cannon-ball from a knowledge of the law ol 

 diminution in its speed. This limit to the variation of species 

 seems to be established for all cases of man's selection. What 

 argument does Darwin offer showing that the law of variation 

 will be different when the variation occurs slowly, not rapidly ? 

 The law may be different, but is there any experimental ground 

 for believing that it is different ? Darwin says (p. 153) : ' The 

 struggle between natural selection on the one hand, and the 

 tendency to reversion and variability on the other hand, will in 

 the course of time cease, and that the most abnormally developed 

 organs may be made constant, I can see no reason to doubt.' 

 But what reason have we to believe this ? Darwin says the 

 variability will disappear by the continued rejection of the 

 individuals tending to revert to a former condition ; but is there 

 any experimental ground for believing that the variability will 

 disappear ; and, secondly, if the variety can become fixed, that 

 it will in time become ready to vary still more in the original 

 direction, passing that limit which we think has just been 

 shown to exist in the case of man's selection ? It is peculiarly 

 difficult to see how natural selection could reject individuals 

 having a tendency to produce offspring reverting to an original 

 stock. The tendency to produce offspring more like their 

 superior parents than their inferior grandfathers can surely be 

 of no advantage to any individual in the struggle for life. On 

 the contrary, most individuals would be benefited by producing 

 imperfect offspring, competing with them at a disadvantage ; 

 thus it would appear that natural selection, if it select anything, 

 must select the most perfect individuals, having a tendency to 

 produce the fewest and least perfect competitors ; but it may be 

 urged that though the tendency to produce good offspring is 

 injurious to the parents, the improved offspring would live and 

 receive by inheritance the fatal tendency of producing in their 

 turn parricidal descendants. Yet this is contending that in the 

 struggle for life natural selection can gradually endow a race 

 with a quality injurious to every individual which possesses it. 

 It really seems certain that natural selection cannot tend to 

 obliterate the tendency to revert; but the theory advanced 

 appears rather to be that, if owing to some other qualities a race 

 is maintained for a very long time different from the average or 



