Ingenuity versus Resourcefulness iii 



flies or for climbing trees? It seems eminently reasonable 

 that the bones of birds should be light and hollow, that 

 the air spaces in the bones should be connected with the 

 lungs: the bird's mode of life demands lightness com- 

 bined with strength. But what shall we say of similar 

 air spaces in the bones, connected with the lungs — in the 

 crocodile? 



On the one hand is the persistence of type under all sorts 

 of conditions. On the other hand is the adaptation of the 

 same structures to the greatest variety of functions. From 

 the point of view of special creation, we should expect not 

 only a direct adaptation of a given species to its place in the 

 world, but an equally direct adaptation of its organs to its 

 special mode of life — ]ust what we do not find. From the 

 point of view of evolution, both the persistence of type and 

 the marvelous plasticity and adaptability of identical struc- 

 tures can be understood as the normal result of descent with 

 modifications. 



Ingemiity versus Kesourcefulness 



Romanes, in his Darwin and after Darwin, stresses the 

 variety of functions to which a particular structure is adapted 

 in different organisms, and the various structures which are 

 adapted to the same function: 



"On the one hand, we meet with structures which are perfectly ho- 

 mologous and yet In no way analogous: the structural elements remain, 

 but are profoundly modified so as to perform wholly different functions. 

 On the other hand, we meet with structures which are perfectly analo- 

 gous, and yet in no way homologous; totally different structures are 

 modified to perform the same functions. How then are we to explain 

 these things? By design manifested in special creation, or by descent 

 with adaptive modification? If it is said by design manifested in special 

 creation, we must suppose that the Deity formed an archetypal plan of 

 certain structures, and that he determined to adhere to this plan through 

 all the modifications which those structures exhibit. But, if so, why is 

 it that some structures are selected as typical and not others? Why should 

 the vertebral skeleton, for instance, be tortured into every conceivable 



