PROPlSR FORM OF THE CHEST. 147 



rax from injury, are powerful agents in extending and contract- 

 ing the chest in the alternate inspiration and expiration ol" air. 



TJie Proper Form of the Chest. — This leads to a very im- 

 portant consideration, the most advantageous form of the chest 

 for the proper discharge of the natural or extraordinary functions 

 of the thoracic viscera. The contents of the chest are the 

 lungs and the heart : — the first, to render the blood nutrient and 

 stinmlating, and to give or restore it to that vitality which will 

 enable it to support every part of the frame in the discharge of 

 its function, and devoid of which, the complicated and beautiful 

 machine is inert and dead ; and the second, to convey this puri- 

 fied arterialized blood to every part of the frame. 



In order to produce, and to convey to the various parts, a suf- 

 ficient quantity of blood, these organs must be large. If it 

 amounts not to hypertrophy, the larger the heart and the larger 

 the lungs, the more rapid the process of nutrition, and the more 

 perfect the discharge of every animal function. 



Then it might be imagined that, as a circle is a figure which 

 contains more than any other of equal girth and admeasurement, 

 a circular form of the chest would be most advantageous. Not 

 exactly so ; for the contents of the chest are alternately expand- 

 ing and contracting. The circular chest could not expand, but 

 every change of form would be a diminution of capacity. 



That form of chest which approaches nearest to a circle, while 

 it admits of sufficient expansion and contraction, is the best — 

 certainly for some animals, and for all under peculiar circum- 

 stances, and with reference to the discharge of certain functions. 

 This- was the grand principle on which Mr. Bakewell proceeded, 

 and on which all our improvements in the breeding of cattle 

 were founded. 



In the heavy draft-horse, the circular chest is no disadvantage, 

 and it gives him, what we require, weight to oppose the weight 

 of his load. Speed is not demanded of him. 



Some of our saddle-horses and cobs have barrels round enough, 

 and we value them on account of it, for they are always in con- 

 dition, and they rarely tire. But when we look at them more 

 carefully, there is just that departure from the circular form of 

 which mention has been made — that happy medium betweer 

 the circle and the ellipse, which retains the capacity of the on< 

 and the expansibility of the other. Such a horse is invaluable foi 

 common purposes, but he is seldom a horse of speed. If he is per- 

 mitted to go his OMTi pace, and that not a slow one, he v^dll work 

 on forever ; but if he is too much hurried, he is soon distressed 



The Broad JDeep Chest. — Then for the usual purposes of the 

 road, and more particularly for rapid progression, search is made 

 for that form of the chest which shall unite, and to as great a 



