THE HORSE AND HIS RIDER. 23 



more limited in range, but it is probably more acute, 

 because the black lining of the human eye renders it 

 a more perfect camera obscura, and gives more vivid- 

 ness to the pictures formed within it. The lining 

 membrane of the horse's eye is of a beautiful sea 

 green color, in consequence of which it absorbs so 

 much the less light, and thereby affords increased 

 power of vision in the night. Every rider must be 

 aware from experience that his horse can discern sur- 

 rounding objects, when the gloom of evening conceals 

 them from his own eyesight. All animals who have 

 to seek their food by night have the interior of the 

 eye more or less bright ; in the wolf and the dog it is 

 grey ; and in all varieties of the cat species it is 

 yellow ; the eyes of the lion have been compared to 

 two naming torches in the night. There are indi- 

 viduals of the human race called Albinos, whose eyes 

 look red like those of ferrets, from the absence of the 

 usual black pigment, and these persons are almost 

 blind by day, but see with ease in what to other men 

 seems thick darkness. 



"Many persons erroneously suppose that the flow 

 of tears, caused by bodily pain or emotions of the 

 mind, is peculiar to man. But Shakspeare says of 

 the wounded stag : 



" The big round tears 



Coursed one another down his innocent nose 

 In piteous chase ;" 



