114 VbeRtts. [Book IX, 



make a confiderable curve, fometimes called their an- 

 gle. The ribs then begin to become broad, and continue 

 fo to their anterior end, whereas near the fpine they 

 are nearly round. To the fore end of each rib a long 

 broad and ftrong cartilage is fixed, and reaches thence 

 to the fternum, or is joined to the cartilage of the next 

 rib. The ribs are twenty-four in number, twelve being 

 placed on each fide. They are divided into the true 

 and the falfe ribs j the feven uppermoft on each fide, 

 which are connected to the fternum, being called true, 

 and the remaining five falfe. 



The upper rib is fo placed, that its connection with 

 the fternum is fomewhat higher than that with the 

 fpine, and the two connections of the fecond rib are 

 about horizontal j all the other ribs, however, point 

 obliquely downwards, as they approach the fternum, 

 and this obliquity increafes as we advance lower. A 

 neceffary confequence of this ftructure is, that when 

 the ribs are raifed, they muft be brought nearer to a 

 right angle with the fpine, and that the cavity of the 

 cheft muft be enlarged. The upper rib is fixed, but 

 the, fecond and every fucceeding rib is-gradually more 

 moveable than that placed immediately above it. 



The feven upper ribs, called the true ribs, are, as 

 was before remarked, connected to the fternum 5 the 

 three upper of the falfe ribs are not connected to the 

 fternum, but adhere to each other, and to the cartila- 

 ginous anterior part of the loweft of the true ribs. The 

 two loweft of the falfe ribs are only connected to the 

 fpine by one articulation, and have their other end no 

 ctherwife fupported than by the mufcles and mem- 

 branes with which they are furrounded. By thisftruo- 

 ture the trunk of the body is rendered more flexible at 

 its lower part, where moft motion is required. 



The ufes of the ribs are to form the lateral parts -of 



the 



