624 COMPARATIVE PHYSIOLOaT. 



In the fastest gallop the length of stride may amount to six 

 to seven metres, and the speed to twelve to fifteen metres per 

 second. In such a rapid gait the contact of the one hind foot 

 produces a sound lengthened by the rapid impact of the fellow- 

 foot. The same applies to the fore-feet, hence only two sounds, 

 while in the other varieties of this gait the interval between the 

 impacts is sufficient to allow of three, or it may be four sounds. 



The accompanying plate, constructed by the help of instan- 

 taneous photography, illustrates the different positions of a 

 horse in the gallop. 



Sloping shoulder-blades and well-bent stifle-joints are gener- 



, ally recognized as of great importance to an animal intended 



for high speed, and these are commonly to be met with in the 



¥m. 474.— Various positions in the Irot (Colin). 



iJeetest of horses, dogs, and other quadrupeds (Fig. 452). It 

 may be seen that such an arrangement permits of a length- 

 ened stride bejng taken with ease, tends to reduce concussion, 

 and adds to beauty of form. To this must, in part at all events, 

 be attributed the grace of form and fleetness of the race-horse 

 and the greyhound, not to mention wild animals. 



A horse for heavy-draught purposes requires great muscular 

 power, which in turn implies a strongly developed osseous sys- 

 tem; and in order that this may be attained some of those 

 principles on which speed depends must be subordinated to 

 those involved in strength. As is well known, the cart-horse 

 and race-horse, the mastiff and the greyhound, are opposites in 

 build and capacity for speed. However, between these extreme 

 forms there are many others of an intermediate character, as 

 the hunter, roadster, etc. When famous race-horses are studied, 



