ANIMAL LOCOMOTION. 65 



feet. The combination one hind foot and two fore feet has not 

 been seen, though no reason can be urged for the non-occurrence. 

 (See especially series 744.) 



Support of the Vertebral Column in the Walk. 



The lateral disposition of the feet in the walk supports the 

 vertebral column at the ends, and the figure of the trunk and 

 limbs compares with a truncated triangle whose base is on the 

 ground. In the diagonal disposition the opposed feet meet at a 

 point near each other under the centre of the trunk (when the 

 other feet are " off"), and the figure compares with that of an in- 

 verted triangle whose curved base is directed upward. 



The animals which assume the diagonal central support are 

 short-legged creatures. The best examples are the raccoon and 

 the baboon. (See p. 72 and p. 75.) The approximation to it is 

 seen in the capybara. It is never seen in the ungulate. 



The Trot. 



In the trot the succession of foot-falls is inclined to synchrony 

 from the circumstance that the motion becomes more constant as 

 the animal increases in speed. 



Thus, in the trot in a series of twenty pictures. 

 Eh is "off" 15. 

 " on" 5. 

 Lf is "off" 15. 

 " on" 5. 

 In 593 — another series---the order is as follows in a series of 

 twelve pictures : 



Rh is " on" 5. 

 "off" 7. 

 Lh is " on" 9. 

 "off" 3. 

 Rf is "on" 4. 

 "off" 8. 

 Lf is"off" 9. 

 "on" 3. 

 The left feet have moved in synchrony. The right feet show 

 a disposition to remain on ground longer, and, therefore, are doing 

 more work. 



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