2 THE BUTTERFLIES OF NEW ENGLAND. 



by night, expand their Avings fully or even incline them downwards when 

 at rest, pass their chrysalis state in a cocoon or beneath the ground, and 

 have no hooks at the tip of the chrysalis ; all these features, however, are 

 liable to frequent exceptions. 



Too-ether with all other lepidopterous insects, the butterfly is well known 

 to undero-o peculiar and, to outward appearance, very sudden transforma- 

 tions durino- its growth ; born as an egg, it emerges from it as a worm-like 

 animal called a cater})illar, which feeds voraciously on the plant upon 

 which the maternal instinct has taught the butterfly to lay her egg, casts 

 its skin several times in its growth, and finally, sloughing its integument 

 ai>'ain, comes out a })upa or chrysalis, in which the creature appears as if 

 in swaddling clothes, all its appendages neatly encased upon its breast, and 

 itself helpless and almost completely motionless, — to ordinary view as 

 different as possible from the aerial creature w^ith variegated tremulous 

 wino's one may see shortly afterward sipping honey from an open flower, 

 or dancing merrily in the sunlight. 



Changes similar to these are now known to occur throughout no incon- 

 siderable portion of the animal kingdom, but they are most familiar to the 

 popular mind and Avere first known to the ancients in the insect tribes and, 

 2)ar excellence in the Lcpidoptera. 



Without entering in full in)on the characteristics of lepidopterous insects 

 in o-eneral, we shall in this introduction first examine the general structure 

 of butterflies both external and internal, in the various stages of existence, 

 as a basis for a knowledge of their proper classification. We shall next 

 outline such a classification by means of a historical survey of former en- 

 deavors ; follow this by a study of the physical features of the territory with 

 whose butterflies and butterfly faunas we have most to do, and close with a 

 special investigation of the earliest beginnings of life within the eggs of 

 butterflies. We shall then be prepared to discuss the different sorts in 

 systematic detail. 



THE EGG. 



AH insects, likewise, lirini;- forth worms, except 

 a ''crtMiii ^-ciuis of luitterllies, and tliese hriiiii- forth 

 a liartl sul)st:iii<-e reseinhlin^- a grain of l)astard 

 sart'ron, l)ut wliicli internally is liciuid. 



AuiSTOTLK," Tnyl'ir^s trandalinn. 



External characteristics (Plates 64-69). 



The eggs of butterflies are composed externally of a thin pellicle, separa- 

 ble into the base, walls and micropyle ; the first is usually flat, destitute of 

 special markings, serving simply as a field of attachment ; the walls are 

 variously sculptured and com})ose the rest of the egg, excepting the minute 

 micropyle, which occupies the very summit, and is made up of a rosette of 

 excessively minute cells. 



