42 SCIENCE IN SHORT CHAPTERS. 



cabbage butterfly and the wide-awake dragon-fly, or the 

 twenty-five thousand possessed by certain species of still 

 more Vigilant beetles. 



Each of these little eyes has its own cornea, its lens, and 

 a curious six-sided, transparent prism, at the back of which 

 is a special retina spreading out from a branch of the main 

 optic nerve, which, in the cockchafer and some other crea- 

 tures, is half as large as the brain. If each of these lenses 

 forms a separate picture of each object rather than a single 

 mosaic picture, as some anatomists suppose, what an awful 

 army of cruel giants must the cockchafer behold when he 

 is captured by a schoolboy! 



The insect must see a whole world of wonders of which 

 we know little or nothing. True, we have microscopes, 

 with which we can see one thing at a time if carefully laid 

 upon the stage ; but what is the finest instrument that Koss 

 can produce compared to that with twenty-five thousand 

 object-glasses, all of them probably achromatic, and each 

 one a living instrument, with its own nerve-branch supply- 

 ing a separate sensation? To creatures thus endowed with 

 microscopic vision, a cloud of sandy dust must appear like 

 an avalanche of massive rock-fragments, and everything 

 else proportionally monstrous. 



One of the many delusions engendered by our human 

 self-conceit and habit of considering the world as only such 

 as we know it from our human point of view, is that of sup- 

 posing human intelligence to be the only kind of intelli- 

 gence in existence. The fact is, that what we call the 

 lower animals have special intelligence of their own as far 

 transcending our intelligence as our peculiar reasoning in- 

 telligence exceeds theirs. We are as incapable of following 

 the track of a friend by the smell of his footsteps as a dog 

 is of writing a metaphysical treatise. 



So with insects. They are probably acquainted with a 

 whole world of physical facts of which we are utterly igno- 

 rant. Our auditory apparatus supplies us with a knowl- 

 edge ef sounds. What are these sounds? They are vibra- 

 tions of matter which are capable of producing corresponding 

 or sympathetic vibrations of the drums of our ears or the 

 bones of our skull, When we carefully examine the sub- 



