30 THE SCIENTIFIC EVIDENCES OF 



flying, by having the fingers enormously elongated 

 and overspread with a membranous web. In 

 birds, again, the arm is modified for flight in 

 a wholly different way — the fingers here being 

 very short and all run together, and the chief 

 expanse of the wing being composed of the 

 shoulder and fore-arm. In frogs and lizards, 

 again, we find hands more like our own ; but in 

 an extinct species of flying reptile the modifica- 

 tion was extreme, the wing having been formed 

 by a prodigious elongation of the fifth finger, and 

 a membrane spread over it and the rest of the 

 hand. Lastly, in serpents the hand and arm have 

 disappeared altogether. 



Thus, even if we confine our attention to a 

 single structure, how wonderful are the modifi- 

 cations which it is seen to undergo, although 

 never losing its typical character ! How are 

 we to explain this ? By design manifested in 

 special creation, or by descent with adaptive 



