118 



THE GENESIS OF SPECIES. 



[CHAP. 



wonderfully folded teeth of the labyrinthodonts. The 

 marvellously complex structure of these organs is not 

 merely unaccountable as due to " Natural Selection," but 

 its production by insignificant increments of complexity 

 is hardly less difficult to comprehend. 



MUCH ENLARGED HORIZONTAL SECTION OF THE TOOTH OF A LABYRINTHODON. 



Similarly the aborted index of the Potto (Perodicticus) 

 is a structure not likely to have been induced by minute 

 changes ; while, as to u Natural Selection," the reduction of 

 the forefinger to a mere rudiment is inexplicable indeed ! 

 " How this mutilation can have aided in the struggle for 

 life, we must confess, baffles our conjectures on the sub- 



