52 ARE THE EFFECTS OF USE INHERITED f 



as fins or flappers for swimming under water in 

 pursuit of fish. 



The reduced size of the wings of these island 

 birds is paralleled by the remarkable thinness, 

 &c., of the shell of the " gigantic land-tortoise " 

 of the Galapagos Islands. The changes seen in 

 the carapace can hardly have been brought about 

 by the inherited effects of special disuse. Why 

 then should not the reduction of equally useless, 

 more wasteful, and perhaps positively dangerous 

 wings be also due to an economy which has become 

 advantageous to bird and reptile alike through 

 the absence of the mammalian rivals whose places 

 they are evidently being modified to fill ? The 

 complete loss of the wings in neuter ants and ter- 

 mites can scarcely be due to the inherited effects 

 of disuse ; and as natural selection has abolished 

 these wings in spite of the opposition of use- 

 inheritance, it must clearly be fully competent to 

 reduce wings without its aid. In considering the 



