THE SKELETON 



63 



in the embryo except upon the theory which is part of the doctrine 

 of evolution that each individual epitomizes in his own develop- 



FIG. 29. 



Fir,. 28. The sternum seen on its ventral aspect. M, manuhrium; C, body; 

 P, ensiform cartilage; Id, notch for the collar-bone; Ic 1-7, notches for the rib- 

 cartilages. 



Fu;. 29. The ribs of the left side, with the dorsal and two lumbar vertebrae, 

 the rib-cartilages and the sternum. 



mental history the evolutionary history of the race to which he 

 belongs. 



The Ribs (Fig. 29). There are twelve pairs of ribs, each being 



