2()9 on caterpillars. Oct. 14 . 



chrysalis can be discovered. The outer envelope of 

 these cocoons, is a substance in every respect resem- 

 bling the outer part of a silk worm's cocoon, only the 

 threads are much more tender, and in smaller quan- 

 tity ; for the greatest part of it consists of a ball con- 

 taining an oblong bag, filled with a kind of thickifli 

 juice, more resembling an egg without a fhell, than 

 any thing to which I can liken it. What animal is 

 to be produced from this egg I fhall be glad to 

 know. 



It appears to me that the insect which ought to be 

 produced from this species of cocoon, has deposited 

 its eggs in the body of the caterpillar, which have 

 there been hatched, like maggots in other animal 

 substances, and which have subsisted on the cater- 

 pillar itself till the time of their transformation ap- 

 proached, when they have burst their confinement, 

 and prepared for another state of existence ; as is 

 common with all animals of this kind. 



The production of a silky web is by no means pe- 

 culiar to the caterpillar genus. The web of a spider 

 is well known ; and several kinds of snails produce 

 occasionally threads of great strength, which they 

 have the power of availing themselves of for tempo- 

 rary uses ; but I know not if any of these retain 

 strength for any permanence of time. I was myself 

 witnefs to the strength of a rope of this sort last 

 summer, which occasioned to me no little surprise. 

 The fact I fhall here relate, to see if any of my rea- 

 ders can' give any satisfactory elucidations on that 

 subject. 



