Ill ON ANIMAL LIFE 91 



facet as an independent eye, in which case 

 many insects realise the epigram of Plato — 



Thou lookest on the stars, my love, 



Ah, would that I could be 

 Yon starry skies with thousand eyes. 



That I might look on thee ! 



Even so, therefore, we only substitute one 

 difficulty for another. 



But this is not all. We have not only no 

 proof that animals are confined to our five 

 senses, but there are strong reasons for believ- 

 ing that this is not the case. 



In the first place, many animals have 

 organs which from their position, structure, 

 and rich supply of nerves, are evidently 

 organs of sense ; and yet which do not 

 appear to be adapted to any one of our five 

 senses. 



As already mentioned, the limits of hearing 

 are reached when about 36,000 vibrations 

 of the air strike on the drums of our ears. 

 Light, as was first conclusively demonstrated 

 by our great countryman Young, is the im- 

 pression produced by vibration of the ether 



