THE TYPES AND CLASSES OF HORSKS 93 



Hayes takes issue with Youatt, who published a fallacy J9 

 concerning the conformation of the ribs that has been re- 

 peated by many English writers, namely, that the circular 

 chest could not expand, but every change of form would be 

 a diminution of capacity. Hayes states that "this state- 

 ment seems to be based on the supposition that the chest 

 expands and contracts by the ribs opening and closing in a 

 direction at right angles to the length of the body. Instead 

 of this being the case, the difference in capacity of the chest 

 is due to the fact of the ribs, which are inclined to the rear, 

 turning round towards the front on their upper and lower 

 ends, as on pivots, when air is drawn into the lungs, and 

 then revolving back again when the air is expelled from 

 them. We may here note that the air is expelled from the 

 lungs by the elastic recoil of the ribs, which takes place the 

 moment the muscles which drew the ribs forward become 

 relaxed. Youatt 's statement is altogether incorrect; for 

 the rounder the ribs are, other things being equal, the 

 greater will be the difference between the chest capacity 

 when the lungs are full, and its capacity when they are 

 comparatively empty." The feature of good length applies 

 rather to rotundity of fore rib, than to the distance between 

 the respective ends, although the ribs far back should be as 

 long and directed as much outward as possible, so as to 

 afford a broad attachment to the diaphragm. "If the last 

 rib be short, flat and but little inclined to the rear, the 

 animal will be 'slack in the loins' and certainly will not 

 have as good breathing power as he would if that rib was 

 long, l springing' well out from the side, and inclined so 

 much to the rear that there would be space only for the 

 ends of two or three fingers between it and the point of the 

 hip." In the case of the draft horse, the greater the arch 

 and length of rib, the more the space available for the de- 

 velopment of muscles and weight so significant a feature 

 of this type of animal. We get neither draft form nor 

 weight in the horse with flat, short rib and wide coupling. 



"The Horse. By William Youatt, London, 1843, New York edition, p. 169. 



