3o6 NATURAL SCIENCE. may. 



narcotics. Practically speaking, all other causes of elimination too 

 slightly effect the survival rate to be causes of evolution : and more- 

 over, these other causes do not, under modern conditions, generally 

 eliminate particular types of individuals ; for example, individuals 

 who perish of starvation, are not necessarily those who are least able 

 to endure prolonged abstinence from food, but generally those who, 

 owing to other causes [e.g. the effects of disease), are unable to pro- 

 cure food ; again, those who perish of drowning are not in particular 

 those who are least fitted to acquire the art of swimming, but quite 

 chance individuals. Little or no evolution, therefore, can result from 

 these minor causes of elimination, and therefore the present evolution 

 of man is in a direction altogether different from his past evolution 

 during which were evolved his physical and mental parts. 



It is possible that had these considerations been present to the 

 minds of my critics, some of their strictures would not have been 

 written. For example, Mr. Buckman says : " It is strange that a 

 work entitled ' The Present Evolution of Man ' should take no 

 account of the reproduction question. For instance, there is at the 

 present day a sudden decrease in the birth-rate. It undoubtedly corre- 

 sponds with the rapidly-spreading knowledge of chemical means for 

 checking fecundation. The less fertile race will inevitably succumb 

 to the more fertile, and this decrease of the birth-rate heralds its 

 disappearance. It is remarkable that a book dealing with the evolu- 

 tion of man says nothing of a factor more important than any it 

 treats." 



But supposing the English, for example, used artificial checks to 

 fecundation and the Irish did not, what, let me ask Mr. Buckman, 

 does he conceive would be the direction of the resulting evolution ? 

 What would be the physical or mental change ? Surely it is 

 clear that, since no particular type of individual would be selected, 

 no evolution could result. Even if the English became alto- 

 gether extinct from this cause and were replaced by the Irish, it 

 is clear that the surviving race would not undergo evolution, since 

 among them there would have been no elimination. In fact, if we 

 premise that congenital or inborn variations are alone transmissible, 

 we must conclude that the evolution of even a very highly complex 

 animal such as man can seldom at any one time have proceeded on 

 very complex lines. His different structures must have been evolved, 

 under the changing stress of Natural Selection, during different but 

 overlapping epochs of a long-extending past. What perceptible 

 evolution, for instance, have such highly important organs as his 

 hands and feet, his eyes and ears, his heart and lungs, etc., under- 

 gone for thousands of years ? When any of these attained such 

 perfection as to place man in harmony with that portion of his 

 environment with which it was concerned, its evolution ceased, and 

 the direction of man's evolution changed. 



If, however, we premise that acquired modifications are trans- 



