NYMIMIAIJXAK: CHARIDRYAS NYCTEIS. 665 



embraced within the limits of this work and west of it, this insect is single- 

 brooded, and iiil)crnatc8 when partly grown, doubtless in crevices afforded 

 by objects lying on the ground ; on emerging in the spring the caterpillar, 

 which then feeds singly, grows slowly until June, when, after spending 

 ten to fifteen days in the chrysalis state, it emerges as a butterfly ; the 

 earliest males appear about the middle of June, but do not become abun- 

 dant until the females emerge, generally early in July ; the latter are not 

 common until the middle of the month, when, or a little later, they begin 

 to predominate, and the males to be worn and dull ; the females continue 

 at least throughout July. 



The eggs must be laid at once, for there is no record of the capture of 

 the female after July and specimens enclosed by Mr. Saunders laid eggs 

 before July 5 ; so, too, caterpillars were found in their second stage on 

 August 20 by Mr. Lintner near Albany. The caterpillars moult two 

 or three times before hibernating, the earliest ones becoming dormant by 

 the middle of July (Saunders) while others are delayed until the end of 

 August (Lintner) . The condition of captured butterflies, however, shows 

 that these all are to be referred to a single brood. 



Further south, the history is a much more complicated one ; we have 

 only the observations of Messrs. Edwards and Riley to guide us, besides 

 our knowledge (from very scattered oljservations) of their habits at the 

 north. These all lead us to conclude that the insect in the latitude of 

 West Virginia and Missouri is partially single and partially double 

 brooded, and not as Mr. Edwards supposes (perhaps from unpublished 

 observations) single, double and triple brooded. This curious condition 

 is brought about by the fact that a portion of the caterpillars born from 

 the first brood of butterflies pass through their stages in an ordinary man- 

 ner and produce in time a second brood the same season ; while another 

 portion lagging at first a little behind their brethren, often from the 

 same batch of eggs, finally pass, at the hibernating age, into a state of 

 lethargy while it is still midsummer or even by the end of June. They 

 even assume at this early period the livery they wear through the winter, 

 which is of a russet color, according to Mr. Edwards, and not black like 

 their brethren of the same age who are not laggards. 



Of niuty-two larvae from oue lot of eggs laid Maj' 28 [writes Mr. Edwards] and all 

 which passed their first moult about Jnne 18, fift.v-six proceeded to second moult 

 about June 21, and third moult about June 26, and so on to chrysalis. But thirty-six 

 lingered after the first moult, and thirty-two of them assumed the russet hibernating 

 coat. . . at second moult, -while the remaining four came up then in black coats, like 

 the larger part of the brood, and slowly proceeded to chrysalis, which they reached 

 many days after the others. These four seemed to have had a tendency to join the 

 hibernators, which was somehow counteracted, but they proceeded with a hesitancy 

 at every stage till they reached chrysalis. [Of the thirty -two all continued lethargic 

 through the season, and some survived the winter.] 



Of the earliest hatched caterpillars of the season about one-third be- 



84 



