156 ORGANIC EVOLUTION CONSIDERED 



have been produced independently of each other. 

 Even if it be granted that they are not homologous in 

 structure, this does not at all relieve the difficulty of 

 accounting for them. 



If, as Darwin says, " it is impossible to conceive by 

 what steps these wondrous organs have been pro- 

 duced," the difficulty is only multiplied by the fact 

 that they have had several, instead of one origin. It 

 is impossible to account for the existence of any one 

 of the electric organs of fishes by natural selection or 

 by any other plausible theory of evolution. 



It is admitted that wings as organs of flight have 

 been independently evolved in at least four different 

 lines — namely, in insects, pterodactyls, birds and bats. 



That an organ so highly specialized as any one of 

 these wings could be evolved seems improbable; 

 while the evolution of the four different kinds, inde- 

 pendently of each other, only increases the improb- 

 ability. 



Romanes admits that if homologous organs were 

 independently evolved the theory of natural selection 

 would be destroyed. 



The difficulty, to my mind, is to account for the 

 evolution of any known kind of wing. In each case 

 there exists the insuperable^ difficulty of preserving 

 the organ through the rudimentary stages. The wing 

 of an insect in the first generation of its evolution 

 would be almost imperceptible and entirely useless 

 for any purpose whatever, and so it would continue 

 to be for a great number of generations. It is evi- 

 dent, therefore, that they could not have been pre- 

 served through their long rudimentary stage on the 

 ground that they were useful, nor do we know of any 

 theory that will account for their evolution. To say 

 that they were evolved is easy, but to account for 

 their evolution seems impossible. 



