THE FORE LEG OR CANNON. 69 



when the foot is elevated, and that then the bone must descend. 

 If the splint bone be depressed when the limb is raised and bent, 

 and have a power of recoiling (which it certainly has), it must 

 aid in throwing the leg into the straight position, and assist the 

 extensor muscles of the knee. Further, we can readily believe 

 that, when the elasticity of these splint bones is lost, by ossification 

 uniting them firmly to the cannon bone, the want of such a piece 

 of mechanism essential to the quick extension of the foot will 

 make the horse apt to come down." 



Supposing the horse's foot to be placed upon a perfectly level 

 unyielding surface, and the weight from above to be thrown upon 

 the limb in a direct line with the centre of motion, " it does not 

 appear," as Sir Charles has observed, " the bones of the carpus can 

 descend." But, supposing the animal's foot to be placed upon an 

 uneven surface, or upon one that becomes so by yielding, may there 

 not be such tilting of the carpal bones from the one-sided dispo- 

 sition of the weight expected to take place as will press downward 

 the splint bone of one side, and so bring both bones into operation 

 alternately or incidentally, as the case may be, depending upon the 

 side to which the weight is inclined, which, commonly, is the inner 

 one 1 According to this view, their operation is, of course, single, 

 and independent of each other : according to former accounts, it 

 was combined and simultaneous. 



It is more than we dare assert, that the splint bone, from any 

 pressure it receives in the bent condition of the joint, does not yield 

 even to the extent of its elasticity, or to use the common phrase, 

 though, as we think, an over-doing one, "descend;" but we cer- 

 tainly must pause ere we can believe such a trifling movement as 

 this so-called descent, after all, can amount to, can have any effect 

 in aiding " in throwing out the leg into the straight position, and 

 assisting the extensor muscles of the knee :" too insignificant a 

 cause, we conceive, to produce an effect so perceptible and so pow- 

 erful. 



Be the operation and use of these elastic powers what it may, 

 few horses retain them after the adult period: the ligamentous 

 elastic material becomes converted into osseous inelastic substance, 

 and thus the three bones, in point of fact, consolidated into one. 

 Do we discover anv difference or alteration in horses' action on 



