THE FALL WEBWORM SNODGRASS. 413 



ing species. Ordinarily webs can be easily removed from small trees 

 by cutting off the supporting twigs or by burning with a kerosene 

 torch. 



The Avebworms that live in Canada, in New York State, and in 

 New England north of the middle of Connecticut are said by some 

 entomologists to be different from the common Ilyphantria cunea, 

 being darker in color and having reddish-brown instead of grayish 

 hairs in the last stage. These have but one generation in a year and 

 the caterpillars spin larger webs. The moths can not be distinguished 

 from the pure white forms of cunea, but none of them ever have any 

 spots on the wings. This northern form is distinguished in name 

 as Ilyphantria textor. When the moths of the two species are caged 

 together the males and females of each mate freely amongst their 

 own kind, but they will not intermarry. These points have all been 

 described by H. H. Lyman in the thirty-second report of the Ento- 

 mological Society of Ontario for 1901. 



It is too bad that we ourselves have reached a mental state so far 

 above the other creatures, because it cuts us off from all communica- 

 tion with them. We are hopelessly above any intimate understanding 

 of the mind of a caterpillar, and as a consequence we are loath to 

 credit it with having any mind at all. Most people do not even know 

 that a caterpillar has a nervous system. Yet it has a brain, a long 

 nerve cord, and nerves that branch to all its parts and regulate its 

 actions the same as ours are governed. But the acts of the caterpillar 

 are attributed by us to what we call instinct, a word that we can 

 pronounce better than we can define. 



Yet, even if we must regard insects as mere automata, unwittingly 

 acting in response to internal stimuli of some sort, the successive 

 adjustment of these impulses to the creature's varying needs is some- 

 thing still beyond our powers of comprehension. A brief outline of 

 the webworm's life will illustrate how all its acts are primed to 

 follow one another in unvarying sequence and to be always operative 

 at the proper time and place. The nervous mechanism may be 

 likened to those bombs of modern warfare which are timed to go off 

 precisely when they reach the mark at which the gunner aims them. 

 With the caterpillar every impulse is prearranged, predestined in 

 the egg, for each individual goes through all the acts of its life in 

 the same rotation. Nature has laid down a curriculum which all 

 that live must follow. In our present state of knowledge we do not 

 know what may be the nature of the commands that drive the 

 creatures on, nor how they are communicated, but an analysis of 

 what is involved would be something like this : The controlling force 

 is located in the central nervous system and is implanted there by 

 heredity, for insects learn nothing by education and serve no appren- 



