REMARKABLE PROVISION. 351 



Insects are also furnished with a contrivance by 

 which they can see objects at a little distance, and 

 objects at a great distance it may be at the same 

 time ; which is more than can be strictly said of 

 ourselves. In men and animals there is a very 

 exquisite apparatus arranged within the eye, by 

 means of which it can accommodate itself to 

 objects close at hand, or again to others at the 

 greatest distance. We can see at one moment a 

 pin at our feet, and at the next the summit of a 

 hill some thirty or forty miles off. Now the laws 

 of light are such, that, to effect this properly, we 

 must have some apparatus in the eye to arrange 

 its focal capacity, so as to receive and concentrate 

 the lines of light proceeding from such different 

 points as the distance of a few inches, and that 

 of many miles. What this apparatus may be is 

 not as yet very satisfactorily determined. But in 

 insects the same result is obtained by a very 

 curious provision. Some of their eyes are short- 

 sighted, and some long- sighted. The simple eyes 

 are supposed, by Professor Miiller, to be the 

 short-sighted eyes, and the compound eyes the 

 long-sighted ones. 



The number of compound eyes in insects does 



