366 



RESPIRATION. 



The ribs differ very materially in their general relations ; thus the 

 upper ones are less oblique than the lower ones, the obliquity in- 



FIG. 206. a, Vertebral column ; 6, clavicle ; d, ribs ; e, sternum. 



creasing as far down as the ninth rib, when it becomes less (Fig. 206). 



FIG. 207. First dorsal vertebra and rib. FIG. 208. Sixth dorsal vertebra and rib. 



Costal Cartilages. These are characterized by their elas- 

 ticity, which is greater in early life, and in the false ribs than in 



