NYMPHAL1D.il. 139 



old unoccupied room ia some outbuildings. Many of them 

 spun the pad of silk from which to suspend themselves, on 

 the under sides of some recumbent green stems of the nettles 

 which had been supplied them for food. These all formed 

 extremely pale pupae — greenish, greenish-grey, or pale drab — 

 while those which crawled away and attached themselves to 

 the walls or woodwork of the room were of the usual brownish 

 or brown-grey colour. 



A curious circumstance in connection with this larva is 

 that, although so completely gregarious that the whole brood 

 may be found crowded together upon the tops of the nettles, 

 until completely full fed, they all then seem utterly to dis- 

 appear. On one day all will be visible, on the next it will be 

 impossible to find one anywhere. I have spent a long time 

 in searching for the spinning-up larvEC or pupee of familiar 

 broods without result, and find that this is an ordinary cir- 

 cumstance, so that very little is known of the kind of position 

 selected by them, in a state of nature, for pupation. 



The butterfly may be found occasionally, though rarely, 

 hybernating in buildings, but its favourite situation for this 

 purpose is evidently in some hollow part of the trunk of a 

 tree, and ilr. E. Newman says that he once found forty speci- 

 mens in a hollow oak. Dr. Plowright, of King's Lynn, found 

 it hybernating among timber lying on the ground, when look- 

 ing for mollusca and fungi, but such a shelter is rarely used. 

 The Rev. Joseph Greene, when digging, in December 18'j2, for 

 moth pupse at the foot of a large beech tree, disturbed three 

 specimens, which were hybernating in the hollow formed by 

 the arching roots, and no doubt this, or a hollow trunk, is the 

 sort of situation usually preferred. 



In this last instance Mr. Greene noticed also the power 

 possessed by this species, as by its allies, of producing a faint 

 hissing sound by the movement of the wiags slowly up and 

 down. ilr. W. C. Hewitson noticed a similar circumstance, 

 but compared the sound to the friction of sand-paper. 

 Mr. Greene's specimens seemed to be under the influence of 



