LECTURE Iir. 121 



support to the twelve ribs, one end of 

 which lies imbedded in cavities formed be 

 tween their bodies, and their tubercles are 

 connected to the transverse processes. 

 The ribs successively and considerably in- 

 crease in length, as far as the seventh, 

 which causes the cavity they encompass to 

 become larger ; they then diminish in 

 length, and the cavity of the chest becomes 

 smaller. The seven upper ribs are connect- 

 ed by gristles to the breast bone. The five 

 lower have their gristles united with each 

 other, or have no connection except with 

 the vertebral column. The breast bone is 

 placed very obliquely, so that at the top it 

 is very near the vertebral column, whilst 

 at the bottom it is very distant. The ribs, 

 in proceeding from the dorsal vertebrae, 

 first take a direction backwards, and then 

 rather suddenly turn forwards, so that the 

 vertebral column projects into the cavity 

 of the chest. This circumstance, and the 

 oblique position of the sternum, both con- 

 tribute to render the weight, before and 

 behind the vertebral column, equiponde- 



