PROTECTIVE RESEMBLANCES IN INSECTS. 53 



beyond this I have not had opportunities of finding out what 

 their persecutors may be. Judging from their protective colora- 

 tion (when at rest) they would appear to be numerous and ever 

 present. 



Giinacia dirce, Linn., is another butterfly frequenting rather 

 similar localities to Ageronia fcronia , but when at rest it closes 

 its wings vertically, and then the elaborate network pattern of 

 dark yellowish brown on a creamy yellow ground matches the 

 lichens covering the tree-trunk on which it rests. The upj)er 

 side had a conspicuous broad yellowish white bar diagonally 

 across the upper wing on a dark ground. 



These two butterflies are good illustrations of the general 

 proposition that the protective colouring and markings are 

 applied to that portion of the insect which is exposed when at 

 rest, the presumable position of danger. We see this illustrated 

 also in the large European red under-wing moth, which, flyin*^ 

 by day, displays in flight the bright crimson lower wing, and is 

 almost invisible directly it alights on the lichen-covered boulders, 

 where the grey-patterned upper wings fold flat over and hide the 

 gaudy lower ones. It is very suggestive also to watch how 

 instinctively and probably unconsciously the European grayling 

 butterfly shrinks down the eye-spot, the only conspicuous part 

 of its under side, and shuts it out of sight beneath the under 

 wing directly it is alarmed by any sudden motion ou the part of 

 the spectator. 



The butterflies which frequent woods in Brazil are an inte- 

 resting study from many points. They are dark in colour — 

 blacks, browns, dark blues, and dull yellows. One would judge 

 from this that their enemies are more numerous in woods than 

 in the open fields. 



Pierella lena, Linn. : a dark yellowish brown is the colour of 

 the dead leaves of the forest trees, over which it flits in a weird 

 gnome-like manner a foot from the ground, choosing in pre- 

 ference to follow the course of a stray leaf-covered forest path- 

 way. The under side of the wings still more closely resembles 

 the dead leaves, even to the veinings and a peculiar dried-surface 

 semitransparent lustre. It is easily overlooked when resting, as 

 it usually does, on the dead fallen leaves, the wings closed, and 

 showing only the under side with its imitative veinings. There 

 is a closely allied species with similar habits, which has orange- 

 brown patches on the lower wings, and it is a curious circum- 

 stance that while these render this butterfly conspicuous while 

 flying, the upper wings are semitransparent, dark brown in 

 colour, and to all appearance calculated to resemble the dead 

 leaves over which it flies, and thus tends towards concealment. 

 The under side of the wings is quite sombre and protective in 

 coloration. 



Myscelia orsis, Drury, is of a beautiful dark velvety blue on 



