8 \ v SCIENCE 127 SHOUT CHAPTERS. 



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 Ross can produce 

 compared to that with twenty -five thousand object-glasses, all 

 of them probably achromatic, and each one a living instru- 

 ment, with its own nerve-branch supplying a separate sensa- 

 tion ? 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 supposing 

 human intelligence to be the only kind of intelligence in exist- 

 ence. The fact is, that what we call the lower animals have 

 special intelligence of their own as far transcending our in- 

 telligence as our peculiar reasoning intelligence 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 ignorant. Our 

 auditory apparatus supplies us with a knowledge of sounds. 

 What are these sounds ? They are vibrations of matter which 

 are capable of producing corresponding or sympathetic vibra- 

 tions of the drums of our ears or the bones of our skull. 

 When we carefully examine the subject, and count the number 

 of vibrations that produce our world of sounds of varying 

 pitch, we find that the human ear can only respond to a limited 

 range of such vibrations. If they exceed three thousand per 

 second, the sound becomes too shrill for average people to hear 

 it, though some exceptional ears can take up pulsations or 

 waves that succeed each other more rapidly than this. 



Reasoning from the analogy of stretched strings and mem- 

 branes, and of air vibrating in tubes, etc., we are justified in 

 concluding that the smaller the drum or the tube the higher will 

 be the note it produces when agitated, and the smaller and the 

 more rapid the aerial wave to which it will respond. The 

 drums of insect ears, and the tubes, etc., connected with 

 them, are so minute that their world of sounds probably begins 

 where ours ceases ; that the sound which appears to us as con- 

 tinuous is to them a series of separated blows, just as vibrations 

 of ten or twelve per second appear to us. We begin to hear 



