240 LEPIDOPTEKA. 



Ti'ouvelot states that the Polj'phemus larva constructs its 

 cocoon by drawing the leaves together as a support for the 

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

 to be the most difficult feat for the worm to accomplish, as after 

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

 regular layers of silk united by a gummj^ substance. The silk 

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

 long. When the cocoon is made, tlie "wc^rm will have moved 

 his head to and fro, in order to distribute the silk, aV)out two 

 hundred and fiftj'-four thousand times. After about half a 

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

 hardty be distinguished through the fine texture of the wall ; 

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

 color, is spread over all the inside of the cocoon. The larA^a 

 continues to work for four or tiA^e da3's, hardly taking a few 

 minutes of rest, and finally 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 

 da}^ previous to its exit, secretes an acid fluid from two glands 

 opening into tlie mouth. This fluid, according to Mr. L. Trou- 

 velot (American Naturalist, A'ol. i, p. 33), in his account of the 

 Polyphemus 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, without breaking a thread. 



Trou velot says that the larvae of the Polyphemus motli 

 seem entirely unable to discern objects with their simple 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 honey, though 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 poAvers of the Polyphemus caterpillar. "It is 

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

 experience in the matter could hardly believe what an amount 



