EVOLUTION OF THE COLORS OF BIRDS. 27 



Having disposed of the theoretical aspect of the ques- 

 tion of use and disuse and the inheritance of acquired 

 characters, a few words on the practical side of the case 

 may now be in order. In the first place it will be advis- 

 able to enquire what an acceptance of the views of 

 Weismann involves. Some of the consequences are 

 well shown by Mr. J. T. Cunningham, in his introduction 

 to the English translation of Elmer's Organic Evolution. 

 He calls attention to the abnormally lengthened tongue 

 of the woodpecker, which can be greatly protruded and 

 thrust into holes to extract insects. The lengthened 

 tongue, the Neo-Darwmians claim, has been produced 

 solely by the selection of those individuals in which it 

 was longest. They cannot but admit with the Lamarck- 

 ians, however, that constant exercise of the tongue in 

 the individual, especially the constant stretching to 

 which it would be subjected in the effort to reach far- 

 ther, would increase its length; but in admitting this 

 they have involved themselves in the paradox of assum- 

 ing that the tongue has become lengthened during the 

 course of ages, and that it has also been lengthened in 

 the individual by the Lamarckian factor of use and dis- 

 use, but that the lengthening which has occurred in the 

 race is in no wise related to the lengthening that has 

 taken place in the individual. " Which is very like the 

 argument," says Cunningham, "that the Iliad and the 

 Odyssey were not written by Homer, but by another man 

 of the same name who lived at the same time." 



Another difficulty in the way of the Neo-Darwinian 

 argument to which Cunningham, among others, has 

 called attention, is its inability to account for the origin 

 of totally new characters. Even though it may be able 

 to account for the lengthened neck of the giraffe by 

 selection, it is impossible, Cunningham argues, to ex- 

 plain the origin of horns by this principle. From what 



