426 illK BUTTEin-LlES OF NEW ENCLAXJ). 



main' times and felt around witli her abdomen, always on the under surface 

 of the leaves, but apparently without satisfaction. Fhially she stopped 

 lonoer than usual on a leaf second or third from the top, alxmt two inches 

 lono", which liad its edges still together, and after she had left I found 

 two large, partially superposed bunches of eggs, 400-500 in all, which she 

 had not had time to lay, so that other females had found this same leaf 

 attractive. Search for eggs at different times with easy success showed that 

 leaves are generally chosen rather above the middle of the upper half of 

 the plant, l)ut not at the extreme summit. The eggs are usually laid with 

 no regularity, in confused heaps, of about three or fom- layers, and an 

 enormous number must be laid by single individuals. I counted 711 in one 

 patch (11.5 mm. long and 1.75 mm. broad), 71o in anotlier (18.5 mm. 

 Ion o- and 9.5 mm. broad), and estimated that a third, which was about 

 20 nun. long and 4 mm. broad had about 500, Avhile a fourth 28 nun. 

 lono- and <"> mm. broad must have contained 900 (64:40). Several 

 times I liave found two or more patches on the same leaf. Sometimes, 

 however, they arc laid in a single layer spread widely over tlie leaf, and 

 H, R. Gilbert once found them "loosely scattered over the upper side, 

 covering nearly half the leaf" (Can. ent., xvii : 187). They are usually 

 laid near the middle of the leaf, and generally on one side only of the 

 midrib. Even when heaped, the eggs usually have a general upright 

 position, especially those next the leaf, but in reality take a good many 

 directions ; adjacent ones, however, lie nmch in the same way, and some of 

 those on top may lie upon their sides. The eggs hatch in about six days. 

 The eo-o-s are very tough and elastic, and adhere strongly to one another, 

 so that they are difficult to separate. 



Food plants. The caterpillars of this butterfly feed upon the common 

 nettle, Urtica dioica L., and doubtless also upon other species, though they 

 cannot be raised, according to Edwards and Gilbert, on the broad leaved 

 species. They feed readily on U. gracilis Ait. Edwards (Hayd. Bull,, 

 iv : 516) says that Mead found them in Colorado feeding in great num- 

 bers on willow ! But Mead himself in Wheeler's Report says he found 

 them on nettle about Denver. 



Habits of the caterpillar. The young creatures on escaping from 

 the egg do not stop to devour them in the least, but after eating a portion 

 or the whole of the leaf on which they are born, climb to the summit of 

 the plant by weaving a silken path ; within a day they smear tlie whole 

 summit with a web and may be seen swarming (for they are highly gre- 

 garious in early life) upon the dried, curving projections of the leaves upon 

 which they soon fasten themselves for a moult. Ihey feed crowded side 

 by side, and on the least disturbance raise their heads and front part of the 

 body at right angles to the rest and wag them slowly in concert, })roduc- 

 ing a ludicrous effect. They are generally found on the upper sinface of 



