1 6 DEGENERA TION, 



before reaching maturity. The fact that no two 

 members of a species are ahke has already been 

 shown to be the starting-point which enables the 

 breeder to make his selection. So, too, with natiu'al 

 selection in the struggle for existence ; the fact 

 that all the young born of one species are not 

 exactly alike — but some larger, some smaller, some 

 lighter, some darker, some short-legged, some big- 

 eyed, some long-tongued, some sharp-toothed, and 

 so on — furnishes the opportunity for a selection- 

 Those varieties which are best fitted to obtain food 

 and to baffle their competitors, gain the food and 

 survive, the rest perish. 



We have, then, to note that the hypothesis that 

 there viust be a selection — which was fram.ed or de- 

 duced as a "test hypothesis" from the earlier hypo- 

 thesis that species have arisen by the action of causes 

 still competent to produce new forms — led j\Ir. Darwin 

 to the discovery of this great cause — the ^^ natural 

 selection',' or " survival of the fittest," In the struggle 

 for existence. Just as the breeder can slowly change 

 the proportions of the animals or plants on which 

 he operates, so In inconceivably long periods of tim.e 

 has this struggling of varieties, and the consequent 



