226 EVOLUTION, GENETICS, AND EUGENICS 



The recognition of consequences — often far-reaching — grows with 

 us as we work with the idea of the web of life, as we see in proper 

 perspective the criminality of those who are ruthless. President 

 Roosevelt has declared his abomination of "the land-skinner" — "the 

 individual whose idea of developing the country is to cut every stick 

 of timber off it, and then leave a barren desert for the home-maker 

 who comes in after him. That man is a curse, and not a blessing to the 

 country. The prop of the country must be the man who intends so 

 to run his business that it will be profitable to his children after him." 

 Every right-thinking man, and especially those who have grasped the 

 idea of the web of life, will say with Roosevelt, "I am against the land- 

 skinner every time." 



It may be said that man must exterminate a good deal if he is to 

 go on peaceably with his business, and it will be admitted that there 

 has never been a strong enthusiasm, humanitarian or otherwise, 

 against the elimination of rattlesnakes, and such like. The natural- 

 ist's answer is that every crusade should be carefully considered on its 

 own merits, and that every careless and hasty destruction of life is to be 

 condemned. Even in regard to snakes killing may be carried too far. 

 Some creatures are, as it were, on the fringes of the web, while others 

 occupy a position where many threads meet. It is scientifically and 

 aesthetically deplorable that birds like the great auk and mammals 

 like the quagga should have been exterminated, but it is practically 

 much more deplorable that we have lost so many hawks and weasels 

 and other members of that pertinacious army whose guerilla warfare 

 keeps hundreds of more humdrum creatures up to the scratch, and 

 keeps "vermin" from becoming a plague. Moreover, it is extremely 

 difficult to tell what may be the consequences of exterminating any 

 creature — remote as it may seem from the beaten track of human 

 affairs. One of the obvious lessons of Darwinism is that we should be 

 slow to call any change unimportant. Everything counts, or may 

 count. A so-called unimportant animal is destroyed and no imme- 

 diate ill effects are seen. But who can tell ? 



Very pertinent, for instance, is the question: What about the 

 parasites that used to complete their life-history in romantic routine 

 in this extinguished animal ? Have we extinguished the parasite also ? 

 Or is it waiting, with a whip of scorpions, to chastise mankind for 

 their ignorance of Darwinism ? 



The practical importance of recognising the web of life has been 

 proved by the heavy penalties which man has often had to pay for 



