70 



THE STRUCTURE OF MAN 



r.p. 



FIG. 50. AN ATTEMPT TO DEPICT DIAGRAMMATICALLY THE PROCESS BY WHICH, FROM 

 THE STUDY OF COMPARATIVE MORPHOLOGY, THE LIMBS OF TERRESTRIAL VERTE- 

 BRATA WOULD APPEAR TO HAVE BEEN PROBABLY DERIVED, BY MODIFICATION, 



FROM THE FlXS OF FlSHES. 



The shaded parts indicate rays which atrophy ; A, pelvic fin of a Sturgeon ; B, 

 diagram of the posterior limb of a larval Salamander ; C, the hind limb of 

 an adult Urodele Amphibian (Ranodori) ; p., pelvis; bs., basale (femur); rd'., 

 proximal rays (tibia, fibula) ; r.p., peripheral ray segments (tarsal and other 

 elements of the pedal skeleton) ; rd". , rays which atrophy and ultimately 

 disappear. 



