394 
SEXUAL SELECTION. 
Part II. 
male, and slightly different in some other respects. In 
an allied Indian form, the Iphias glaucippe, the orange- 
tips are fully developed in both sexes. In this Iphias 
the under surface of the wings marvellously resembles, 
as pointed out to me by Mr. A. Butler, a pale-coloured 
leaf; and in our English orange-tip, the under surface 
resembles the flower-head of the wild parsley, on which 
it may be seen going to rest at night . 6 The same 
reasoning power which compels us to believe that the 
lower surfaces have here been coloured for the sake of 
protection, leads us to deny that the wings have been 
tipped, especially when this character is confined to the 
males, with bright orange for the same purpose. 
Turning now to Moths : most of these rest motion- 
less with their wings depressed during the whole or 
greater part of the day ; and the upper surfaces of their 
wings are often shaded and coloured in an admirable 
manner, as Mr. Wallace has remarked, for escaping 
detection. With most of the Bombycidse and Noc- 
tuidse , 7 when at rest, the front-wings overlap and 
conceal the hind-wings; so that the latter might be 
brightly coloured without much risk ; and they 
are thus coloured in many species of both families. 
During the act of flight, moths would often be able 
to escape from their enemies ; nevertheless, as the 
hind-wings are then fully exposed to view, their bright 
colours must generally have been acquired at the 
cost of some little risk. But the following fact shews 
us how cautious we ought to be in drawing conclu- 
sions on this head. The common yellow under-wings 
6 See tlie interesting observations by Mr. T. W. Wood, * The Stu- 
dent/ Sept. 1868, p. 81. 
7 Mr. Wallace in c Hardwicke’s Science Gossip,’ Sept. 1867, p. 193. 
