EVIDENCES OF EVOLUTION 43 



instances of Owen, to whom it owes its classic 

 statement : 



(1) The wing of a bird and the arm of a 

 rnan; they are both fore-limbs, with funda- 

 mentally the same structure as regards bones 

 and muscles, nerves and blood-vessels; they 

 are homologous, but not analogous. 



(2) The wing of a bird and the wing of a 

 huitscfly; they are both organs of true flight, 

 but they have no structural or developmental 

 resemblance; t^y a^rQ ^,na.lngonsf. but not 

 homologous. 



(3) The JTOlff of ft bi>d nnH thg wing of 



a bat: they are both fore-limbs of similar 

 structure and development; they are both 

 organs of true flight; they are at once ho t - 

 mologous and analogous. 



Now, the evolutionary suggestiveness of 

 homologies is indisputable. If we take, for 

 instance, a series of fore-limbs among back- 

 boned animals the arm of a frog, the paddle 

 of a turtle, the wing of a bird, the fore-leg of 

 a horse, the flipper of a whale, the wing of a 

 bat, and the arm of man we find detailed 

 homology not only as regards the bones, but 

 as regards muscles, nerves, and blood-vessels. 

 Throughout there is qfosQ similarity ? n f ^ e 

 fundamental. material ^nd in the_mode j)f 

 origin^ but the ^^J_je^\j.Jta,JtLOJK>. different! 

 Tnere is moulcfing and shaping and twisting 



