SPECIAL SENSES OF INSECTS. IS 



pillars with a broad black band around its body. The 

 mantis put up her front feet in the usual attitude and 

 the caterpillar promptly took hold of the tarsi. Nothing 

 happened until the caterpillar bit viciously at the mantis's 

 foot, when she jerked her foot away and ran off, going on 

 five legs and holding up the sixth, much as a dog holds up 

 an injured member. 



In an insect the tiny nerve at the apex of the hair 

 runs down under the skin to a knot of nervous matter, 

 and from there a nerve fiber runs to a nerve ganglion for 

 that particular segment on which the hair is located. 

 The ganglion is a part of the whole nervous system, as 

 will be proved by the fact that the insect may will to run 

 away as the result of this excitation of one of its tactile 

 hairs, or it may will to turn about and show fight. Try 

 this on a caterpillar, removing as far as possible the 

 chance of its seeing you and thus becoming frightened in 

 that way. 



This is different from the usual conception of the 

 human nervous system, where all impressions are sup- 

 posed to be referred to the forward end of the nerve axis — 

 the brain — ^for interpretation. But -we are coming to 

 realize, through more intelligent study, that there are 

 plenty of stimuli coming in upon our nervous system, 

 which are interpreted before reaching the cerebrum; in 

 fact, so far as late investigators can determine, some 

 stimuli never reach the brain at all, but pass into action 

 upon being interpreted elsewhere. This, being true, 

 proves again the similarity of life activities. Our life 

 is, at foundation, of the same sort as the life of these sim- 

 pler creatures; only in us it finds more varied means of 

 expression. 



