IIE.Sl'KRIUI : TIIANAOS JUVENALIS. 1483 



portion is not brought to tlie vcrv surface of the leaf — are also often covered 

 l)_v a thin net work of dciicntc, tissue-like silk of the same color. Riley states 

 that one found by him "had fastened a lobe of one leaf to another leaf just 

 below it wiiii stout cords of a yellowish silk ; the base of each of these cords 

 was broadened so as to give more strength to the cord ; the worm," he 

 adds, "is very courageous and if touched on tlic al)domen, turns around and 

 endeavors to bite the intruder, and it is with the greatest difficulty that 

 one can remove the worm from its tent without injuring the cords, on ac- 

 count of the resistance of the caterpillar" ; this T have also found to be the 

 case. 



It travels on the leaf some distance from its nest for food, even in 

 its earliest stage. One hatched in confinement did not at first build any 

 nest, but resided generally on the under siu'face of the leaf. I removed it 

 to the upper side of a fresh o.ak leaf. It travelled for an hour or two, 

 over to the under surface and then back again, and finally took uj) its 

 residence on the upper surface, ate a cut about a millimetre deep at the 

 edge of the leai' and during the next niglit the parenchyma of the upper 

 surface at a little distance from it. Tlicn it returned to its station on the 

 upper surface and remained there. It is impatient, however, of confine- 

 ment in early life. This one died before moulting, and another in its third 

 stage, shut up in a jelly glass with oak leaves, appeared very unhappy, 

 wandering everywhere, off as much as on the oak leaves, which were 

 perfectly fresh. On leaving an old nest to construct a new one, when half- 

 grown, it always bites off the silken strands of its old abode. 



It ordinarily rests quietly by day upon the upper surface of its nest, 

 back downward, feeding or working only by night ; when disturbed, it 

 opens its jaws widely and scrapes the surface of the leaf backward rapidly 

 and repeatedly, making a scratching noise on the rough veins of the leaf. 

 About the middle of September or sometimes not until the middle of 

 Octolier,* the caterj)illar stops feeding and begins at once to close all the 

 openings to its abode with a slight, but very tough silken film ; this occupies 

 four or five nights ; the whole cavity is also lined thinly with silk to enable 

 it to move securely to any part. Shoidd any accident afterwards happen 

 to the nest, the whole is at once filled anew, but the silk is then of a white 

 color. 



Kiley remarks that "the color of these larvae is of the same pale bluish 

 green as the lower surface of the leaves of the chestnut-oak [on which he 

 found them] and the whole surface is covered with small roundish, very 

 pale yellowish-white spots," which Mrs. Peart observes are so closely 

 crowded as to give the caterpillar a mealy appearance. When ready for 



♦ It sometimes moults for the last time when doors as late as October 27; indeed the cater- 

 most of the leaves are brown and none entirely pillar eats more or less until the last week in 

 green, and I have had the moult occur within November. 



