504 THE SENSORIAL FUNCTIONS. 



and especially those whose bulk is great, as 

 the Elephant, the Rhinoceros, and the Hippo- 

 potamus, have comparatively small eyes; for 

 that of the elephant does not exceed two 

 inches in diameter. The eye of the Whale is not 

 much more than the 200th part of the length 

 of the body. When the natural food of an 

 animal is stationary, and requires no effort of 

 pursuit, the eye is generally small, and the 

 sight less keen ; while in the purely carnivorous 

 tribes, which are actively engaged in the chase 

 of living prey, the organ of vision is large and 

 occupies a considerable portion of the head ; the 

 orbit is much developed, and encroaches on the 

 bones of the face ; while, at the same time, the 

 bony partition separating the globe of the eye 

 from the temporal muscle is supplied by ligament 

 alone : so that when that muscle is in strong 

 action, the eye is pressed outwards, giving to 

 the expression of the countenance a peculiar 

 ferocity. 



While nature has thus bestowed great acute- 

 ness of sight on pursuing animals, she has, 

 on the other hand, been no less careful to arm 

 those which are the objects of pursuit, with 

 powers of vision, enabling them to perceive 

 their enemies from afar, and avoid the impend- 

 ing danger. Thus, large eyes are bestowed 

 on the Rodentia and the Ruminant ia. Those 

 tribes which pursue their prey by night, or 



