REST ATTITUDES—COSMOPOLITANS 575 
Opened again when cloud passed. [Compare the observation on 
Teracolus ione, p. 549, supra.] 
Recently M. J. Th. Oudemans has published an interesting 
memoir entitled “ Etude sur la Position de Repos chez les Lepi- 
dopteres.” 1 
M. Oudemans treats of only one aspect of the subject, but this 
he deals with exhaustively by numerous observations on living 
specimens of all the chief groups of Macrolepidoptera. His con¬ 
clusions may be shortly expressed, almost in his own words, thus :— 
Lepidoptera have a sleeping-dress; this dress forms a harmonious 
whole. The different parts which contribute to form the whole dress 
harmonize in their colours and usually in their patterns. 2 The parts 
of the insect which are concealed during rest are quite frequently 
strongly contrasted in colour or pattern to the exposed parts. M. 
Oudemans explains the facts by the influence of exposure to light. 3 
M. Oudemans does not allude to the points chiefly dealt with in 
this section, but one of his beautiful photographs shows Chrysophanus 
phlaeas , Linn., sitting with abdomen tilted up at an angle of about 
45° to the thorax, as I have shown in the figure of Euchloe belemia , 
Esp., on Plate V. He does not, however, call attention to its peculiar 
attitude. That it must greatly increase the resemblance to a dead 
leaf is obvious enough. 
§ 12. Cosmopolitan Lepidoptera. 
Next to novelties and rarities the insects that interest me most 
are the commonest species, and more especially those to which the 
adjective “ cosmopolitan ” may fairly be applied. We know next to 
nothing of the conditions which determine whether a species shall be 
scarce or abundant, local or widely spread. 
It may be of interest to append a list of such species as I have 
in my wanderings found in districts far apart. 
Polyommatus baeticus, Linn. 
Simla, 1903; Peshawar, 1903; Khaibar Pass, 1903; Malakand, 
1 Verhandelingen der Koninklijke Akademe van Wetenschappen , vol. x., No. 1 . 
Amsterdam, 1904. (Read at Berlin, International Congress of Zoology, August, 
1901.) 
2 Compare my remarks on the green Noctuid from New Zealand, Erana grami- 
nosa , Walk., p. 468, supra. 
3 Compare Dr. M. Standfuss, Die Beziehungen zwischen Fdrbung und Lebensge- 
wohnheit bei den Palaearctischen Grossschmetterlingen. Vierteljahrsschrift der natur- 
forsch. Gesellschaft in Zurich, xxxix Jahrgang, 1894. (Read November 6th, 1893.) 
