MUSCLES AND TENDONS. 29 



and for sustaining the exertion he may be called upon 

 to undergo. In the cart-horse, on the contrary, thickness 

 of muscle is the greatest desideratum, always supposing 

 that he has sufficient activity to walk well, and occasion- 

 ally to trot at a moderately brisk rate. As a thin muscle 

 will contract at least as quickly as a thick one of the same 

 length, it follows that an increase in the thickness of 

 muscles is useful only in making the work more easy, 

 and that it does not otherwise add to the speed. Massive 

 muscles, compared to slight ones, have two disadvantages, 

 namely — they increase the weight which is carried, both in 

 muscle and bone ; and they necessitate the possession 

 of large joints, which, from increased friction, are not 

 so easily bent and extended as smaller ones ; besides, it 

 has been proved that they do not respond as quickly 

 to nervous stimulus. Although it is impossible to lay 

 down any exact rules on this subject, we may say, speaking 

 generally, that the thickness of muscle which would be 

 commendable in a weight-carrying hunter, would be 

 quite out of place in a race-horse, as we may see by com- 

 paring Fig. 385 with Fig. 384. We may often observe 

 that race-horses which were very smart as two-year-olds, 

 lose their " form " after that age without any assignable 

 reason, except that as they "thickened," they got slow. It 

 is instructive to note that those speedy animals, the 

 cheetah, greyhound, and antelope, like the race-horse, are 

 comparatively narrow behind, and that the hind-quarters 

 of the cart-horse are wide (Fig. 335). The muscular 

 development to be sought for in the race-horse, in order 

 to enable him to carry weight (within racing limits) and 

 to stay, should be obtained with a minimum increase to 

 the burden the animal has got to move ; and is to be 

 looked for chiefly in the loins, gaskins, and fore-arms, 

 with great rotundity and comparative length of the back 

 ribs, and comparative thickness of bone just below the 

 hocks. In this respect, Ormonde (Frontispiece), St. 

 Gatien, Bendigo (Fig. 50), Isonom}^, Barcaldine, and 



