70 The Book of Cats. 



proving that when the external light is wholly 

 excluded, none can be seen in the Cat's eye. For 

 the same reason, the animal, by a change of pos- 

 ture or other means, intercepting the rays, imme- 

 diately deprives the observer of all light otherwise 

 existing in, or permeating, the room. In this action, 

 when the iris of the eye is completely open, the 

 degree of brilliancy is the greatest ; but when the 

 iris is partly contracted, which it always is when 

 the external light, or the light in the room, is in- 

 creased, then the illumination is more obscure. 

 The internal motions of the animals have also great 

 influence over this luminous appearance, by the 

 contraction and relaxation of the iris dependent 

 upon them. When the animal is alarmed, or first 

 disturbed, it naturally dilates the pupil, and the 

 eye glares ; when it is appeased or composed, the 

 pupil contracts, and the light in the eye is no 

 longer seen. 



A German savant says, that at the end of each 

 hair of a Cat's whiskers is a sort of bulb of nervous 

 substance, which converts it into a most sensitive 

 feeler. The whiskers are of the greatest use to 

 her when hunting in the dark. The nervous bulbs 

 at the ends of a lion's whiskers are as large as a 

 small pea. 



