144 



THE GENESIS OF SPECIES. 



[CHAP. 



Whenever the remains of bats have been found they 

 have presented the exact type of existing forms, and there 

 is as yet no indication of tlie conditions of an incipient ele- 

 vation from the ground. 



The pterodactyls, again, though a numerous group, are 

 all true and perfect pterodactyls, though surely some of 



WING-BONES OF PTEBODACTYL, BAT, AND BIRD. 



the many incipient forms, which on the Darwinian theory 

 have existed, must have had a good chance of preservation. 

 As to birds, the only notable instance in which discov- 

 eries recently made appear to fill up an important hiatus, is 

 the interpretation given by Prof. Huxley 3 to the remains 

 of Dinosaurian reptiles, and which were noticed in the 

 third chapter of this work. The learned professor has (as 

 also has Prof. Cope in America) shown that in very impor- 

 tant and significant points the skeletons of the Iguanodon 

 and of its allies approach very closely to that existing in 

 the ostrich, emeu, rhea, etc. He has given weighty rea- 

 sons for thinking that the line of affinity between birds and 



3 See also the Popular Science Review for July, 1868. 



