THE AMERICAN ENTOMOLOGIST. 



193 



projection, which has sometimes been likened 

 to a Roman nose, growing ont of the middle of 

 its back. This projection, however, is not a 

 peculiarity of this particular species, but oc- 

 curs in the pupa; of all the species belonging to 

 this genus (2\^i/mph(dis) , the transformations of 

 which are known. 



The I)isi2)2nis butterfly, as is correctly stated 

 by Harris, is double-brooded; but that author 

 is entirely wrong in asserting that the second 

 brood passes the winter in the pujja state.* He 

 probably jumped to this conclusion from finding 

 the butterfly flying about so early in the spring- 

 (but it could not have had sufficient time to 

 hatch out from the egg and acquire its full 

 larval growth the same season; and with its 

 wings so bright and unworn, that it could not 

 have hybernated in the butterfly form, as do 

 certain allied species (Vanessa Antiopa and 

 several species of Grapta) . The real truth of 

 the matter is, that the autumnal brood of larvfe 

 have only attained about one-third their full 

 size when the winter sets in, and hybernatc in 

 a singular house (Fig. 134 c), which they con- 

 struct for this purpose out of the leaf of the 

 willow. First and foremost — with wise fore- 

 thought, and being well aware through its natu- 

 ral instincts, that the leaf which it has selected 

 for its house will fall to the ground when the 

 cold weather sets in, unless it takes measures to 

 prevent this — the larva fastens the stem of the 

 leaf with silken cables securely to the twig from 

 which it grows. It then gnaws off the blade of 

 the leaf at its tip end, leaving nothing but the 

 mid-rib, as shown in Figure 134 d. Finally, it 

 rolls the remaining part of the blade of the leaf 

 into a cylinder, sewing the edges together with 

 silk, the gnawed portion of the leaf forming a 

 long flap which is bent down and fastened by 

 silken cords so as to act as a door to the house. 

 The basal portion of the cylinder is of course 

 tapered to a point, as the edges of the leaf are 

 merely drawn together, not overlapped; and 

 invariably the lower side of the leaf forms the 

 outside of the house, so as to have its projecting 

 mid-rib out of the way of the larva, as it re- 

 poses snugly in the inside. The whole when 

 finished (Fig. 134 c), has somewhat the appear- 

 ance of the leaf of a miniature pilcher-plant 

 (Sarracenia'), its length being 0.50 — 0.U.3 inch, 

 and its diameter 0.11 — 0.14 inch. 



We liave found these winter-houses in the 

 summer time, old, dry and empty, on the 

 Heart-leaved Willow (iSa/ix cordata) ; and on 

 April 18th, ISii.i, and for a week or two subse- 

 quently we found great numbers of recent ones 



• Injurious Insects, p. iS-2. 



on the Humble Willow (S. Ilumilis), some few 

 of them still containing the larva, but most of 

 them empty and with the larva in the immedi- 

 ate neighborhood, crawling sluggishly about 

 and nibbling the catkins of this willow, which 

 were then in full flower but not yet in leaf. We 

 placed a lot of these larvae in a breeding-cage 

 and fed them upon willow; and from this lot 

 we bred one pupa on May .Oth, and four others 

 between that date and May loth. The first but- 

 terfly appeared May 21st, and two afterwards 

 on May 24th. We have also bred the butterfly 

 on August loth, from a pupa found in the open 

 air suspended from the stem of a grass-plant in 

 the woods, and of course belonging to the first 

 brood of larvie.* 



No other American butterfly has hitherto been 

 recorded as hybernating in the larva state, and 

 this is the first complete account that has yet 

 been published of the singular mode in which 

 tliis process is accomplished by the larva of the 

 Disippus butterfly.f Not the least wonderful 

 part of the phenomenon is, that it is only the 

 autumnal brood of larvte that form pitcher-like 

 houses to live in during the inclement season of 

 the year, the summer brood having no occasion 

 to shelter themselves from the cold. We thus 

 have an instance of a curious architectural in- 

 stinct being only developed in alternate genera- 

 tions ; which is much the same thing as if, with 

 a certain race of men, the great-grandfathers, 

 the fathers and the grandchildren ran wild in 

 the woods, and the grandfathers, the sons and 

 the great-grandchildren lived in houses and led 

 the life of civilized human beings. 



Society of ^'alul■at History/, Stiv -JT, 

 (tildes \v eknuwji both tu -Mi". Tiini 

 Ijoiii at least as early as the year 1807. 



