348 THE LIFE OF AN INSECT. 



We are unable to enter into further particulars 

 upon the structure and functions of this beautiful 

 apparatus; but it must be added, that 

 the following is the manner in which 

 the ray of light becomes perceived by 

 the insect. It first passes through the 

 facet (a), next enters the cone (6), then 

 strikes upon the nerve (c) which con- 

 veys the impression, taking the large 

 nerve (d) to the brain. The colouring 

 layers are intended to prevent any rays 

 of light from passing to other parts of 

 |P the insect's eye, and so confusing the 

 A si^ie facet se- impressions made upon its senses by 



paratcd and 



magnified. external objects. 



The number of these facets, or, if we choose to 

 call them so, distinct eyes, varies in different 

 insects. In some there are comparatively few, in 

 others an amazing multitude. The following list 

 of their number is given by Miiller, as observed 

 by various entomologists : 



In the Ant there are 50 



Convolvulus Sphinx .... 1,300 



Common House-fly .... 4,000 



Silk- worm Moth 6,236 



Goat Moth 11,300 



