THE DAY OF THE MOTH 103 



widely spread. This plan serves it well enough when it 

 bivouacs on the trunks of trees which resemble its own 

 mottled brown, but it is by no means difficult to detect on 

 the grey rind of a beech, or on wooden palings of grey or 

 yellow tints. Indoors, where its plan of protection could 

 hardly be expected to apply, it will fix itself on a buff 

 distempered wall, or some such situation where it is as 

 conspicuous as possible. We may conclude, however, that 

 the willow beauties which betray themselves are in the 

 minority, and that the greater number perch on protective 

 backgrounds and are never noticed. The buff-tip moth, of 

 which the gregarious caterpillars strip the boughs of oaks 

 and elms in August and September, emerge in June, and sit 

 with wings wrapped cylindrically round them on posts and 

 trees. When so arranged, the fore-part of their wings 

 imitates a dead twig with silvery bark, and the buff-tip the 

 broken end of the dead wood. But broken dead twigs an 

 inch long are not usually found adhering vertically to the 

 sides of the tree-trunks ; and in such a position the little buff 

 semi-circle is a mark to catch the eye. On the whole, 

 however, the more closely resting moths are hunted the 

 more exact and striking the imitative adaptations appear. 

 The shade of an apple-tree in August is a pleasant place, 

 and it is worth while to spend a few minutes day by day in 

 looking for a resting marbled green moth. Its markings of 

 green and frosted silver make it a beautiful insect, even 

 when pinned to a board, but more fascinating still is to see 

 how wonderfully it imitates the lichen on which it rests. The 

 caterpillar feeds on lichen on walls, and is equally elusive. 



The power of the female to attract certain moths is 

 utilised by collectors with more success than either light or 

 sugar. The process is known as ' sembling,' or assembling. 

 If a newly emerged female emperor moth is placed in a 



