120 PROBLEMS OF EVOLUTION 



the porpoises derive their food from the water, their oxygen 

 from the air, not trying to wring from the sea what it can only 

 supply in meagre amount. For fish there are not the same 

 possibilities. They may compete with one another as they will, 

 or develop what adaptations are possible for defeating one 

 another in the struggle, yet the prizes attainable by the winners 

 are strictly limited by the physical conditions under which they 

 live. Consequently they have been unable to rise to that high 

 state of physical vigour which must be attained before, through 

 the mitigation of the incidence of Natural Selection upon the 

 young, a further advance is made possible. 



I have now shown how the shielding of the young by their 

 parents till they reach maturity, their exercise and their play, 

 help to lessen the waste of indiscriminate elimination. There is 

 another way in which the family system with its various de- 

 velopments forwards the process of evolution, and this will be 

 dealt with under the next heading. 



VII 



INFLUENCE OF THE INDIVIDUAL ON THE EVOLUTION OF THE RACE 



Natural A variation, if it is to forward the process of evolution, must 

 Selection j iave selection-value in the first individuals in which it appears. 



using J ' 



Lamarck- A mere rudiment to be some day, when fully developed, useful to 

 method" ^ ar ~^ descendants, is not a thing that a clear-headed evolutionist 

 can speak of seriously. The fore-limb of the avian-reptilian 

 ancestor of birds must have been serviceable to him as an oar 

 or a wing or as a compound of the two. It cannot have been a 

 reptile fore-limb spoilt and a mere prophecy of a wing. How- 

 ever imperfect, its usefulness must have been in the present, not 

 in the future. When new circumstances arise, there must be, 

 in individuals that are to survive, a fairly complete adaptation 

 ready to hand. The antelopes cannot say to the cheetahs, 

 " Give us a respite of a hundred generations and we shall be 

 able to race you." Somehow the antelope has found a way out 



