LIMENITIS I. 



In relating the history of MeHt;\?a Phaeton, I have shown how caterpillars work 

 in community for protection against the winter. In the present case we see the 

 individual taking care for itself, and with what forethought, mechanical skill, and 

 patience the end is secured. Some caterpillars cover themselves in a web, or 

 bind two leaves together loosely ; more conceal themselves under wood and stone, 

 or in the sod ; but here is one who has turned tailor, weaver, and house-builder. 

 It knows jiist what sort of leaf to choose for its purpose, takes its own measure- 

 ment, cuts out the pattern on a system peculiar but eflfective, sows it up. and 

 inserts an elastic silk band which will be its security when the drying leaf con- 

 tracts, upholsters the interior, binds the stem of the leaf firmly to the brancli, 

 and takes possession, even having provided against the ingress of water by a flap 

 shaped when the pattern was cut out. One cannot but wonder how such a habit 

 originated and how it is perpetuated. Young birds are supposed to make obser- 

 vations on the nest they were fledged in, and so prepare themselves to build a 

 similar one when the proper time comes ; but this caterpillar never saw anything 

 like its winter house, and the butterfly which laid the egg from ^yhich the cater- 

 pillars came knew nothing of houses. In the event of there being a summer 

 as well as a foil bi"ood of one of these case-making species, as in the southern 

 Disrppus and Ursula, the larva3 of the early broods need no shelter, as they 

 take no rest, but proceed through all the larval stages to maturity and to chrys- 

 alis, and this habit of house-building manifests itself, therefore, only in the alter- 

 nate generations. Nothing in the life-history of a butterfly seems more won- 

 derful than that the egg should invariably- be laid on the food plant proper to 

 its caterpillar; for very few caterpillai-s are omnivorous, but nearly all will feed 

 on two or three, and often on one species only of plant, and if they do not 

 find the right plant they die of hunger. It would seem as if the butterfly has 

 a remembrance of her former caterpillar state. Now she is as different as pos- 

 sible, a creature of the sun and air, eating no solid food, for she has no mouth, 

 but lives on liquids drawn up through a tube ; then she was a crawling worm, 

 and voraciously fed on leaves, cutting them with powerful jaws. And between 

 these stages there has intervened another that would seem to have divided them 

 completely, certainly to have extinguished all recollections in the butterfly'. 

 And yet she seeks the particular plant her caterpillar must feed on, and finds it.^ 



' At Coalbiirgh the larvce of Disippus feed on willow, and no aspen grows in this part of the State. In the 

 Catskills, both willows and aspens abound, and there this species prefers to feed on the latter. I have often 

 found their cases on young aspens late in the fall, but never on willow, though willow would be used if there 

 ■was no choice. In 1876, I brought several small aspens to Coalburgh and planted, and since that time I find 

 many larvse of Disippus feeding on the leaves; but on the willows near by, on which I had been accustomed 

 to find them, I rarely have met one. Here was a case where perhaps for hundreds of generations neither 

 caterpillar nor butterfly could have seen an aspen, but the moment one was produced the butterfly knew what 

 would suit the caterpillar best, and deserted the willow. 



