POINTS. 403 



be of a comparatively brief duration. The period of change is snortened ; 

 at tlie same time a larger absorption of the vivifying agent becomes 

 absolutely imperative. The greater depth of chest in the racer admits 

 of a greater change of dimension ; then air is inhaled equal to the ra- 

 pidity of movement. The pace, therefore, can be maintained with com- 

 parative ease. But the round form of thorax allows of little enlargement : 

 the demands made by exertion cannot be complied with, and the heavy 

 horse, when hurried, is consequently soon exhausted. 



It is not, therefore, the size or dimension of its thorax which fits the 

 steed to the purposes of fleetness. That quality depends on the adapt- 

 ability of the cavity to the exigencies of excitement; for such purposes, 

 the quadruped with a round chest is not to be preferred. At present 

 there is no instrument by which the motions of the horse's ribs can be 

 accurately ascertained : thus the reader is forced to guess at an altera- 

 tion which cannot, under existing circumstances, be regarded with that 

 confidence which is inspired by the knowledge of a fact. A quarter of 

 an inch between the enlargement of the ribs in different animals (sup- 

 posing the other points equal) should more than determine the winner 

 of a race, since the change which takes place in the blood regulates the 

 other properties of vitality. 



The belly and the chest are distinct cavities, although there is com- 

 munication between the organs of each. Thus the great artery which 

 originates at the heart, travels into the abdomen ; while the veins which 

 traverse the larger division also penetrate the thorax. Nevertheless, 

 the contents and the uses of each space are generally distinct. The 

 principal agents of the more forward cavity are the heart and the lungs, 

 the thorax being chiefly sacred to the purposes of respiration and of cir- 

 culation. The liver, the stomach, the spleen, and the intestines are 

 inclosed within the abdomen, the function of this region being engrossed 

 by the offices of appropriation or by those of nutrition. 



Most judges admire the horse which presents a belly apparently well 

 filled by its contents. Certainly this appears to be the soundest of the 

 many prejudices which appertain to horse flesh. The shape of the thorax 

 must, in no unimportant degree, regulate that of the abdomen, the two 

 cavities being only parted by a fleshy screen denominated the diaphragm. 

 The herring-gutted quadruped is commonly as deficient in the respiratory 

 as it is wanting in the nutritive functions. Of course this rule is not 

 absolute ; but a capacious thorax is required to counteract any absence 

 in the process of nutrition. The animal which rapidly narrows toward 

 the flank generally purges upon work, is commonly of a washy consti- 

 tution, and usually possesses a bad appetite. Such a retainer will fre- 

 quently spoil more fodder than it will consume ; while the little eaten 



