Chap. XI. Butterflies and Moths. 325 



the males of some of the Leptalides, which imitate protected 

 species, still retain in a concealed manner some of their original 

 characters. Thus in the males " the upper half of the lower 

 " wing is of a pure white, whilst all the rest of the wings is 

 " barred and spotted with black, red aud yellow, like the species 

 • they mimic. The females have not this white patch, and the 

 " males usually conceal it by covering it with the upper wing, 

 " so that I cannot imagine its being of any other use to them 

 " than as an attraction in courtship, when they exhibit it to the 

 " females, and thus gratify their deep-seated preference for the 

 " normal colour of the Order to which the Leptalides belong." 



Bright Colours nf Ciiti rpillar!<. — Whilst reflecting on the 

 beauty of many butterflies, it occurred to me that some cater- 

 pillars were splendidly coloured ; and as sexual selection could 

 not possibly have here acted, it appeared rash to attribute the 

 beauty of the mature insect to this agency, unless the bright 

 colours of their larvae could be somehow explained. In the 

 first place, it may be observed that the colours of caterpillars do 

 not stand in any close correlation with those of the mature 

 insect. Secondly, their bright colours do not serve in any 

 ordinary manner as a protection. Mr. Bates informs me, as an 

 instance of this, tliat the most conspicuous caterpillar which he 

 ever beheld (that of a Sphinx) lived on the large green leaves of 

 a tree on the open llanos of South America ; it was about four 

 inches in length, transversely banded with black and yellow, 

 and with its head, legs, and tail of a bright red. Hence it 

 caught the eye of any one who passed by, even at the distance of 

 many yards, aud no doubt that of every passing bird. 



I then applied to Mr. Wallace, who has an innate genius for 

 solving difficulties. After some consideration he replied : " Most 

 " caterpillars require protection, as may be inferred from some 

 " kinds being furnished with spines or irritating hairs, and 

 " from many being coloured green like the leaves on which they 

 " feed, or being curiously like the twigs of the trees on which they 

 " live." Another instance of protection, furnished me by Mr. J. 

 Mansel Weale, may be added, namely, that there is a caterpillar 

 of a moth which lives on the mimosas in South Africa, and 

 fabricates for itself a case quite indistinguishable from the 

 surrounding thorns. From such considerations Mr. Wallace 

 thought it probable that conspicuously-coloured caterpillars 

 were protected by having a nauseous taste ; but as their skin 

 is extremely tender, and as their intestines readily protrude 

 from a wound, a slight peck from the beak of a bird would 

 bo as fatal to them as if they had been devoured. Hence, at 



