FIELD AND STUDY 



of hand it attaches its cocoon to the end of a branch, 

 I suppose one would need to witness the process. 



In October these preparations and transforma- 

 tions in the insect world are taking place all about 

 us, and we regard them not. The caterpillars are 

 getting ready for a sleep out of which they awaken 

 in the spring totally different creatures. They tuck 

 themselves away under stones or into crevices, they 

 hang themselves on bushes, they roll themselves up 

 in dry leaves, and brave the cold of winter in tough 

 garments, woolly or silky, of their own weaving. 

 Some of them, as certain of the large moths, do 

 what seems like an impossible stunt: they shut 

 themselves up inside a tough case, or receptacle, 

 and attach it by a long, strong bit of home-made 

 tape to the end of a twig, so that it swings freely in 

 the wind. I have seen the downy woodpecker trying 

 to break into one of these sealed-up, living tombs 

 without avail. Its free, pendent position allows it to 

 yield to the strokes of the bird, and all efforts to 

 penetrate the case are in vain. 



How the big, clumsy worm, without help or hands, 

 wove itself into this bird-proof case, and hung itself 

 up at the end of a limb, would be a problem worth 

 solving. Of course it had its material all within its 

 own body, so is not encumbered with outside tools 

 or refractory matter. It was the result of a mechan- 

 ical and a vital process combined. The creature 

 knew how to use the means which Nature had given 

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