156 



BKITISH BUTTEEFLIES. 



some larvae in confinement that they walked with a slow gliding 

 movement, very snail-like, crawling over the surface of a leaf. The 

 larva, at this time, eats through the whole substance of a leaf, and from 

 any part of it, cutting out round or oval holes in the centre, or curved 

 pieces at the side, the head tucked underneath, and quite hidden by 

 the protuberant prothorax, whilst eating. In confinement, it appears 

 to eat freely, both by day and night, but still appears to prefer to rest 

 on the underside of a leaf, where its position, owing to the play of 

 light and shade on the striped sides, makes it most difficult to detect in 

 nature. We have, after a very windy night, occasionally seen larvae 

 crawling up the trunks of an elm-tree, where they form most con- 

 spicuous objects. Concerning this, Thornewill notes that, on June 

 13th, 1888, he found a large number of larvae, near Burton-on-Trent, a 

 large proportion fullfed, and some already turned brown. Many w 7 ere 

 found climbing up the trunks of trees, principally, of course, of the 

 wych-elms, but several on larch, one on ash, and one on a frond of 

 fern, whither it had probably dropped from an elm above. They 

 seemed most to favour such trees as were somewhat exposed to the 

 rays of the sun, and especially such as had seed hanging on them ; and on 

 one of this kind he says that he took nearly twenty larvae. A high wind 

 had been blowing the day before, which might partly account for the 

 numbers found crawling up the trees. All, however, were ascending, 

 not descending. May this, he asks, be an indication of the fact that they 

 pupate towards the top of the tree? Marowski notes (in litt., 1905) 

 that, in the neighbourhood of Berlin, he finds the larvae solely on elms, 

 and only on those of which the south side is in the shade. The larva, he 

 says, "rests on the underside of the leaves, and its coloration and 

 markings are so adapted to those of the underside of the leaf, that it is 

 only possible for the trained eye to find it when it is situated on the 

 lower branches. When the larva is thrown from the tree by the wind, 

 or other mechanical causes, it draws its body, as it lies on the ground, 

 into a half turn like a screw, through which it so much resembles the 

 calyces of the elm-blossoms, which cover in thousands the ground 

 under the elms in May, as to be confused with them. Then, when 

 after a little time it considers the danger past, it retakes its normal 

 shape and creeps towards the elm trunk and up this again." 

 Voelschow's remarks (Ent. Jahrbuch, v., p. 155) are very remarkable, 

 and his conclusions highly improbable. They are to the effect that, 

 when he first discovered the larvae at Schwerin, there were two in 

 company, both already in the umber-brown stage preceding pupation ; 

 both crawled quickly up an elm-trunk, closely, one behind the other, 

 and, when placed in a breeding-cage, proceeded again in single file. 

 The fact that he had also found pupae in nature, more often in twos 

 than singly, spun closely together against a branch, and that, in each 

 case, the hinder was a $ , led him to suppose that the fullfed 2 larva 

 possesses a certain sexual attraction, which incites the $ larva to 

 follow it. We suspect this to be merely a matter of chance, especially 

 as the larvae so rarely pupate on anything but the underside of a leaf 

 in nature, and one suspects pupae found on branches had been formed 

 from larvae that had been disturbed (by wind, etc.) when fullfed. 

 Borgmann notes that at Cassel, the larvae can be obtained freely 

 by beating the elms, where the avenue known as the " Easenallee " 

 crosses the " Lindenburg," but that they are also frequently found 



