THE CHEST. 223 



and commonly called the true, or, more properly, sternal ribs, extending from 

 the spine to the sternum. The remaining nine are posterior and shorter, and arc 

 only indirectly connected with the sternum. 



The ribs are united to the corresponding vertebrae or bones of the spine, so as 

 to form perfect joints or, rather, each rib forms two joints. The head of the 

 rib is received between the vertebrae and bones of the spine, before and behind, 

 so that it shall always present two articulating surfaces, one opposed to the ver- 

 tebra immediately before, and the other to that immediately behind, and both 

 forming one joint, with a perfect capsular ligament, and admitting of a rotatory 

 motion. The head of the rib seems to be received into the cartilaginous liga- 

 mentous substance between the vertebrae. Nothing could be more admirably 

 devised for motion, so far as it is required, and for strength of union, that can 

 scarcely be broken. 



Before the ribs reach the sternum, they terminate in a cartilaginous prolonga- 

 tion, or the lower part of the rib may be said to be cartilaginous. There is 

 between the bony part and this cartilage a joint with a true capsular ligament, 

 and admitting of a certain degree of motion ; and where it unites with the ster- 

 num there is a fourth joint, with a perfect and complete capsular ligament. 



The cartilage of the posterior ribs are united to the bony portion by a kind 

 of joint. They are not, however, prolonged so far as the sternum ; but the 

 extremity of one lies upon the body of that which is immediately before it, 

 bound down upon it by a cellular substance approaching to the nature of liga- 

 ment, yet each having some separate motion, and all of them connected indi- 

 rectly with the sternum by means of the last sternal rib. It is an admirable 

 contrivance to preserve the requisite motion which must attend every act of 

 breathing, every extension and contraction of the chest, with a degree of 

 strength which scarcely any accident can break through. 



The sternum, or breast-bone, is more complicated than it at first appears to be. 

 It constitutes the floor of the chest, and is a long flat spongy bone, fixed between 

 the ribs on either side, articulating with these cartilages, and serving as a point 

 of support to them. It is composed of from seven to nine pieces, united together 

 by cartilage ; and whatever changes may take place in other parts of the frame, 

 this cartilage is not converted to bone even in extreme old age, although there 

 may, possibly, be some spots of ossific matter found in it. 



The point of the breast-bone may be occasionally injured by blows or by the 

 pressure of the collar. It has been, by brutal violence, completely broken off 

 from the sternum ; but oftener, and that from some cruel usage, a kind of 

 tumour has been formed on the point of it, which has occasionally ulcerated, and 

 proved very difficult to heal. 



The front of the chest is a very important consideration in the structure of 

 the horse. It should be prominent and broad, and full, and the sides of it well 

 occupied. When the breast is narrow, the chest has generally the same appear- 

 ance : the animal is flat-sided, the proper cavity of the chest is diminished, and 

 the stamina of the horse are materially diminished, although, perhaps, his speed 

 for short distances may not be affected. When the chest is narrow and the fore 

 legs are too close together, in addition to the want of bottom they will 

 interfere with each other, and there will be wounds on the fetlocks, and bruises 

 below the knee. 



A chest too broad is not desirable, but a fleshy and a prominent one ; yet even 

 this, perhapi, may require some explanation. When the fore legs appear to 

 recede and to shelter themselves under the body, there is a faulty position of the 

 fore limbs, a bend or standing over, an unnatural lengthiness about the fore parts 

 of the breast, sadly disadvantageous in progression. 



There is also a posterior appendix to the sternum, which is also cartilaginous. 



