240 LEriDorTERA. 



Ti'onvclot states that the 1-olyphcnins larva constructs its 

 cocoon by drawing the leaves together as a support for the 

 threads, forming tlie foundation of the cocoon. "This seems 

 to be tlie most diflicult feat for tlie Avorm to accomplish, as after 

 this the work is simply meelianical, the cocoon being made of 

 regular layers of silk iniited by a gummy substance. The silk 

 is distributed in zig-zag lines of about one-eight of an inch 

 long. When the cocoon is made, the Avorni will have mo\cd 

 his head to and fro, in order to distribute the silk, al)Out tvo 

 hundred and fifty-four thousand times. After about half a 

 day's work, the cocoon is so far completed that the worm can 

 hardly be distinguished through the fine texture of the wall ; 

 tlien a gummy, resinous substance, sometimes of a light brown 

 color, is spread over all the inside of the cocoon. The larva 

 continues to work for four or live days, hardly- taking a few 

 minutes of rest, and finall}^ another coating is spun in the 

 interior, when the cocoon is all finished and completely' air- 

 tight. The fibre diminishes in thickness as the completion of 

 the cocoon advances, so that the last internal coating is not 

 half so thick and so strong as the outside ones." 



In those moths which spin a thick cocoon, the pupa, a few 

 daj'S previous to its exit, secretes an acid fluid from two glands 

 opening into the mouth. This fluid, according to Tilr. L. Trou- 

 vclot (American Naturalist, vol. i, p. 30), in his account of the 

 Polyphennis silk-worm, dissolves the hard gummy substance 

 uniting the silken threads, until after the expiration of half an 

 hour, the moth is able to push the fibres aside, and work its 

 way out, Avithout breaking a thread. 



Trouvelot says that the larvae of the Polyphemus moth 

 seen entirely unable to discern objects with their shnple eyes, 

 but can distinguish light from darkness. A supposed auditory 

 apparatus is situated at the base of the abdomen in moths. 



In their adult state butterflies and moths take but little food, 

 consisting of hone^', th.ough Papilio Turnus, according to a 

 Canadian observer, is attracted to heaps of decaying fish. 



Caterpillars grow very rapidly, and consume a great quantity 

 of food. Mr. Trouvelot gives us the following account of the 

 gastronomical powers of the Polyphemus caterpillar. "It is 

 astonishing how rapidly the larva grows, and one who has no 

 experience in the matter could hardh* believe what an amount 



