ANIMAL MOTION. 189 



the lion and both camels, Arabian and Bactrian, amble so 

 that the right foot does not go in front of the left, but 

 follows it.* The phrase used by him to denote movement 

 in diagonal succession is tara ^nxf^eTpov (kata diametron) , and 

 is fully explained in his De Anim. Incessu, c. 14, where he 

 says that the left hind limb is moved after the right front 

 limb, then the left front limb, and, finally, the right hind 

 limb. The camel ambles by moving the right feet and the 

 left feet alternately, the right front and hind feet striking 

 the ground simultaneously, or nearly so, and then the left 

 feet. The peculiarly unpleasant feeling experienced when 

 riding a camel is due to this mode of progression. In the 

 giraffe also the amble is particularly well seen, and it is 

 sometimes seen in the horse, lion, and many other animals. 

 The statement that the right foot does not go before the left, 

 but follows it, is not clear. Pliny's translation, in Nat. 

 Hist., xi. 105, makes the left foot follow the right, and has 

 been adopted by many commentators. Considering the nature 

 of the amble, neither the right nor the left limbs can be pro- 

 perly said to follow the others. There is not sufficient reason 

 for assuming that the Greek text has been tampered with, 

 but it seems to be intended to distinguish between progression 

 Kara, ^lauerpov, in which the traces of the right feet often cross 

 those of the left, and the amble, called by Aristotle taTo. axej^og, 

 or leg by leg, in which the right pair of limbs and the left 

 pair of limbs swing past each other without crossing. 



Aristotle knew that some relationship existed between 

 the arms of Man, the forelegs of quadrupeds, the wings of 

 birds, and the pectoral fins of fishes, which are known to be 

 homologous. His views on this relationship will be con- 

 sidered further in Chapter xv. 



Among the numerous statements made by him about 

 the locomotory parts and the movements of progression of 

 particular animals or groups of animals, the most important 

 are those relating to the elephant, camel, birds, fishes, 

 cephalopods, and crustaceans. Some of these statements 

 will be discussed next. 



Aristotle says : " Animals have the joints of their limbs, 

 anterior and posterior, turned oppositely to one another, 

 and, with the exception of the elephant, oppositely to those 

 of Man, for, in viviparous quadrupeds, except the elephant, 

 the front legs are bent forwards and the hind legs back- 



* H. A. i. c. 5, s. 7, ii. c. 1, s. 8. 



