PROGRESSIVE MOTION IN QUADRUPEDS. 499 



of the head and of the very long neck upon 

 all the legs ; for the length of the neck is fully 

 equal to that of the trunk. It is evident that if 

 the body had been placed in the usual horizontal 

 position, the anterior extremities would have 

 had to support the whole of the enormous weight 

 of this neck and head. This peculiarity of 

 structure, however, introduces considerable mo- 

 difications in the mode of progression of the 

 animal. The ordinary pace of the cameleo- 

 pard is the amble ; but it has also a slower 

 walking pace, and occasionally a gallop. In 

 the amble, its undulation is so considerable as to 

 give it the appearance of being lame. A similar 

 kind of limping gait, arising from the same 

 cause, namely, the disproportionate elevation of 

 the fore part of the spine, has been observed in 

 the Hycena. 



5. Ruminantia. 



IN following the series of Mammalia in the order 

 which best exhibits their successive stages of de- 

 velopement, I shall commence with those whose 

 digestive apparatus is formed to extract nourish- 

 ment exclusively from the vegetable kingdom. 

 The first assemblage that presents itself to our 

 notice is the remarkable family of Ruminants, 





