POINTS. 401 



The muscles last alluded to all originate from the trunk, the more for- 

 ward cavity of which is known as the cfiest. There is much dispute 

 concerning the best form of the horse's thorax ; but such a question can 

 only be decided by the uses to which the animal is to be subservient. 

 For instance, below is inserted the illustration of a cart horse with an 

 almost circular chest. Such a form permits the presence of a huge pair 

 of lungs, and favors the increase of weight. 



A CART HORSE. 



Sufficient oxygen is always present to convert the starch or the sugar 

 of the food into fat : during slow work, enough of atmosphere to vitalize 

 the blood must be inhaled, nor is excessive exertion calculated to mate- 

 rially increase the amount. Where weight is more desired than activity, 

 where propulsion is to be chiefly accomplished by bringing the heavy 

 carcass to bear against the collar, such a make is admirable. All creat- 

 ures, in which speed is not required, should possess circular chests ; for 

 by such a shape the quadrupeds are adapted for the accumulation of fat, 

 and for the performance of slow, of continuous, or of laborious work. 



There are, however, numerous animals which are required to possess 

 capability for a "burst;" for the acme of which phrase is embodied in 

 the rush or the closing struggle of the race-course. The creature of 

 speed, therefore, should exhibit rather the deep than the round thorax ; 

 for fat is not desired on such an animal. The deep cavity, moreover, 

 admits of an expansibility which is imperative during the extremity of 

 muscular exertion. It is, however, sad to see well-bred animals in and 

 about the metropolis forced to pull carts, for which employment nature 

 has unfitted them. They possess no weight of body with which to move 

 the load. The burden must be propelled by the almost unaided power 



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