396 ANATOMY OF THE DOG. 



has not the power of contraction beyond its natural limits. A, 

 medium transverse diameter is therefore to he desired, and is 

 practically found to he advantageous, in allowing a better action 

 of the shoulder-blades rolling upon the surface on each side. 

 On the other hand, man requires great depth of chest from 

 before backwards if he is to have good wind, and the lateral 

 diameter is of less importance. These facts ought to be taken 

 into consideration in selecting the best kind of frame for the 

 purposes of speed and endurance. 



Large size of lone contributes to the strength of the limbs, 

 and foxhounds especially, which have continual blows and strains 

 in their scrambling over or through fences of all kinds, require 

 big limbs and joints. When, however, extreme speed is desired, 

 as in the greyhound, there may be an excess of bone, which then 

 acts as so much lumber, and impedes the activity. Still, even in 

 this dog, the bones and joints must be strong enough to resist 

 the shocks of the course, without which we constantly find them 

 liable to fracture or dislocation. If, however, a dog is brought 

 up at liberty, and from his earliest years is encouraged in his play, 

 the bones though small are strong, and the joints are united 

 by firm ligaments which will seldom give way. 



The dog has no collar-bone, so that his fore quarter is only 

 attached to the body by muscular tissue. This is affected chiefly 

 by a broad sling of muscle, which is attached above to the edge 

 of the shoulder-blade, and below to the ribs near their lower 

 ends. It is also moved backwards by muscles attached to the 

 spine, and forwards by others connected in front to the neck and 

 head, so that at the will of the animal it plays freely in all 

 directions. 



