LIST AND SHADOW 
563 
the minimum of risk. As far as the evidence at present available 
goes this explanation commends itself as the most probable. 
Dr. Chapman tells me that he has observed a marked list in a 
Spanish species of Erebia, and my own experience of list is confined 
to the Satyrines, a group of feeble flyers, be it noted, with (at any 
rate in the great majority of species) cryptic under-sides. 
As regards other families, I have come across but one reference to 
such a habit among the Pierines. Mr. W. H. Edwards, in his 
“ Butterflies of North America/' 1897, quotes Mr. William Couper’s 
observation as to a habit of Colias philodice, Godart, in Anticosti:— 
“ When it alights on a flower, instead of being erect on its feet 
it lies sideways, as if to receive the warmth of the sun.” 
The original passage occurs in the “ Canadian Entomologist,” vol. 
vi. p. 92, 1874; if therefore this be truly such a list as is under dis¬ 
cussion, Mr. Couper deserves the credit of having first recorded it, 
but at present I am doubtful on the point. 
Professor Poulton, in a discussion at the Entomological Society, 
stated that on one occasion many years ago, he had observed a pro¬ 
nounced movement in the nature of a list in the Green Hairstreak 
{Theda rubi). The butterfly was observed at rest on the flat surface 
of a leaf at Birdlip, Gloucestershire, and it let itself down so com¬ 
pletely that it seemed to lie flat on the leaf. The obliteration of 
shadow was very marked, and had at the time forced itself upon his 
mind as the significance of the attitude. 1 
Mr. Bowland-Brown said that he had also observed an extreme 
list in the same butterfly. He has since been good enough to call 
my attention to a note in No. 13 of the Bulletin de la Societe Entom. de 
de France, 1909, pp. 211,212, on the egg-laying habits of Pararge maera 
and P. megaera, in which it is stated that the latter, creeping in to 
lay her eggs, lies almost flat on the ground—“ elle plie ses ailes, 
rentre les ailes superieures entre les ailes inferieures, puis les 
incline parallelement an sol; elle entre alors sous les brins de 
l’herbe . . .” (J. de Joannis). 
Dr. T. A. Chapman 2 has published some interesting notes on 
heliotropism, and more especially on list in Callophrys {Thecla) rubi 
and Thestor ballus. 
Mr. L. B. Prout netted a specimen of the Green Hairstreak which 
settled on his finger in such a position as resulted in the vertical 
exposure of the under surface to the sun. When Mr. Prout moved 
his finger the butterfly changed its position in a corresponding 
1 Proc. Ent. Soc. Lond., 1906, p. xxviii. 
2 Entomological Record , vol. xviii., 1906, p. 168. 
