THE BACKGROUND OF DARWINISM ADAPTATIONS 193 



FIG. 40. Three aquatic types of vertebrate, to illustrate convergent adapta- 

 tion of three wholly unrelated forms of marine life. All three show the fusiform 

 body, median and paired fins, though the skeletal structures are radically differ- 

 ent. A, shark (Pisces); B, ichthyosaur (Reptilia); C, porpoise (Mammalia). 

 (From Newman, after Osborn.*) 



