92 Animal Life and Intelligence. 



that we are not at present considering how any of these 

 resemblances have been brought about ; we are merely 

 indicating that, given certain resemblances, advantageous 

 either for captor or prey, those organisms which possess 

 them not will have to suffer elimination — elimination by 

 enemies, or else elimination by competition. 



The interaction between these two kinds of elimination 

 is of great importance. Hunters and hunted are both, so 

 to speak, playing the game of life to the best of their 

 ability. Those who fail on either side are weeded out ; and 

 elimination is carried so far that those who are only as 

 good as their ancestors are placed at a disadvantage as 

 compared with their improving congeners. The standard 

 of efficiency is thus improving on each side; and every 

 improvement on the one side entails a corresponding 

 advance on the other. Nor is there only thus a competition 

 for subsistence, and arising thereout a gradual sharpening 

 of all the bodily and mental powers which could aid in 

 seeking or obtaining food ; there is also in some cases a 

 competition for mates, reaching occasionally the climax of 

 elimination by battle. There is, indeed, competition for 

 everything which can be an object of appetence to the brute 

 intelligence; and, owing to the geometrical tendency in 

 multiplication — the law of increase — the competition is 

 keen and unceasing. 



Such, then, in brief, are the three main modes of 

 elimination : elimination by physical and climatic condi- 

 tions ; elimination by enemies ; elimination by competition. 

 Observe that it is a differentiating process. Unlike the 

 indiscriminate destruction before alluded to, the incidence 

 of which is on all alike, good, bad, and indifferent, it 

 separates the well-adapted from the ill-adapted, dooming 

 the latter to death, and allowing the former to survive and 

 procreate their kind. The destruction is not indiscriminate, 

 but differential. 



Let us now turn to cases of selection, properly so called, 

 where Nature is in some way working at the other end of 

 the scale ; where her method is not the elimination of the 



