1234 THE BUTTERFLIES OF NEAV ENGLAND. 



cies, our own, is said to exhale a disagreeable odor (though I could 

 perceive none in a fresh male), another a strong musky odor, and in the 

 neighboring genus Ithobalus, where the fold is wanting, the males have 

 sometimes tAvo classes of odors, according to Fritz Miiller. 



Tiie more or less complete history of all the species is known. They 

 are digoneutic or polygoncutic and supposed to winter as butterflies. The 

 eggs hatch in a week or more, the caterpillars mature in two or three 

 weeks, and the chrysalids hang from two to four weeks ; the ratio of pupal 

 to larval life being exceptionally large and the more remarkable in an 

 insect which does not appear to hibernate in the chrysalis stage. The 

 eggs are laid in small and rather open clusters, and the caterpillars feed 

 openly but on the underside of leaves, sometimes alone, sometimes in 

 small companies on Aristolochia and occasionally on allied plants. 



The eggs are nearly globular and covered with a waxy secretion in ver- 

 tical ridges which give it somewhat the appearance of a melon. 



The juvenile caterpillars are cylindrical, covered with series of conical 

 tubercles, highest in front and behind, most of them bearing only a single 

 tapering bristle a little longer than the segments. After the first moult, 

 these are exchanged for short fleshy tubercles of subequal length, a con- 

 dition which is perpetuated in the neighboring genus Ithobalus. In the 

 mature caterpillars, hoveever, these are unequal and the first pair extremely 

 long; the body, which "becomes more elongated" (Harris) is of a rich 

 dark brown, the longer tubercles red on the basal half, the shorter ones 

 wholly pale yellow. 



The chrysalids are green or red and very oddly formed ; the inferior 

 curve of the body is strongly sinuate, the back of the thorax furnished 

 with a very prominent pyramidal ridge, the base of the abdomen strongly 

 and roundly expanded on the sides, while the segments behind are con- 

 spicuously ridged on either side of the back. 



EXCURSUS XLVII.—A STUDY OF CERTAIN CATERPILLARS. 



All iiieu are worms : but this no man. In silk 

 'Twas brought to court first wrapt, and white as milkj 

 Where afterwards it grew a butterfly, 

 "Which was a caterpillar: so 'twill die. 



Ben Jonson.— On Court- Worm. 



The bug, which you would fright me with, I seek. 

 Shakespeare.— Winter's Tale. 



Interesting as are the transformations of a butterfly in the three 

 earlier periods of its life, marked off by such strict lines from one another, 

 the changes which the same insect undergoes in shape, in color and in 

 clothing in the different stages of caterpillar life alone, are scarcely less 



