USE AND DISUSE OF ORGANS. 15 



animals, it is still in my opinion not without a use 

 in the economy in which it occurs. The small 

 wings of the wing-powerless birds, for example, are 

 not useless, though they do not enable the animals 

 to fly. The wings of the ostrich aid it in running ; 

 the wings of the penguin serve as paddles in swim- 

 ming. 



What Mr. Darwin, following Lamarck, says of 

 the use and disuse of organs use as the cause 

 of increased development, disuse as the cause of 

 deterioration of structure appears to me to be the 

 result, in a great measure, of ill-observed and ill- 

 explained facts > and therefore no argument in support 

 of his doctrine, as he illogically imagines. 



That animals have had their form and structure 

 and, consequently, their functional endowments 

 transmuted by Natural Selection or any other process 

 of Evolution in a long course of ages, and that they 

 have thereby become adapted for habits and a mode 

 of life different from those for which their ancestors 

 were originally created, are propositions not supported 

 by any legitimate induction from real facts. 



Very exaggerated and illogical notions pass 

 current as to the effects of use and disuse on organs. 

 Enlargement and increased physical strength are 

 considered the proper effects of use ; diminution of 

 size and impaired physical strength the proper 

 effects of disuse; whatever be the nature of the 

 organ in question, though this is really applicable 



