78 



THE STERNUM. 



[CHAr. 



seven segments altogether in the sternum (Fig. 35). The 

 presternum is narrow, rounded in front, and bearing the 

 first pair of sternal ribs close to its apex. The succeeding 

 pieces gradually widen, the posterior segments of the meso- 

 sternum being square, flat, and rather massive (especially in 



t 



1 



Fig. 35. — Sternum and sternal ribs of 

 the Red Deer [^Cervus elaphus), \. ps 

 presternum ; ms mesosternum ; xs 

 xiphisternum. 



Fig. 36. — Sternum of the Pig {Sus 

 scrqfa), \. ps presternum ; )iis meso- 

 sternum ; xs xiphisternum. 



the Giraffe) ; they are hollowed at the middle of their 

 lateral borders. The xiphisternum is thin and flat. 



In the Pig (Fig. 36) and Hippopotamus the presternum 

 is compressed and keeled ; the articular facets for the first 



