NYMPHALID^E. 7 



wliicb hang by tlieir tails only, show, in tlie straight ventral surface of the abdomen 

 of the vast majority of them, that they are descended from butterflies which in their 

 chrysalis stage were also girt about the middle. 



Although other families contain butterflies which vie with the Nymphalidge iu 

 lustrous beauty, this largest family contains upoa the whole by far the greatest 

 number and variety of striking forms, whether we consider the butterfly, the egg^ 

 the caterpillar, or the chysalis. There is also here a greater variety of structure 

 than is found in any of the other families of butterflies. The colouring of the wings 

 is also more vaiied than in other families, and more than in any other will one 

 discover a striking difference between the colouring of the upper and under surface 

 of the wings. 



As oae departs further and further from the lower Lepidoptera in ascending 

 the families of butterflies, we discover a lai'ger proportion of those which, when at 

 rest, raise the wings above the back and expose ouly the under surface, instead of 

 expanding the wings horizontally and so showing the upper surface, as in Moths. It 

 is therefore upon the under surface of the wings of butterflies that we should look 

 for a greater variety of colouring than upon the upper surface, at least in the higher 

 forms; and this is exactly what we find. 



Here, too, occur the greatest number of cases of protective resemblance and of 

 mimicry. 



Nor is the interest especially attaching to this family confined to structure and 

 colouring alone. In habits and in life-histories the diversity of the type is every- 

 where displayed. For there is scarcely any variation in the regular cycle of changes 

 which every lepidopterous insect undergoes which is not found within the limits of 

 this family, and many are confined entirely to it. They pass the winter in every 

 possible change excepting, so far as is known, in that of the egg, but including in 

 one or other group every stage of larval life. The caterpillars are more often social 

 than in other groups. There frequently enters also an element of lethargy even in 

 midsummer. The behaviour of caterpillars for their protection against their 

 enemies is exceedingly varied and interesting, and the forms of shelter constructed 

 for their concealment are equally varied. The mode of pupation, is, as already 

 stated, different from that of any other group, in tliat they hang by their tail alone, 

 and in general quite freely, though there are a few instances, as Cirrochroa, in which 

 the pad of silk is so tightly woven to the surface upon which it is spun, and the cremastral 

 hooks of the chrysaUs are spread over so long a surface that the chrysalis, instead of 

 hanging freely, lies with its ventral surface in close proximity to the surface of rest. 

 The method in which they accomplish their transformations, from the caterpillar 

 clasping the pad of silk with its anal prolegs to the chrysaUs whose hinder end, 

 armed with little anchor-like hooks, is withdrawn from the shrivelled skin of the 



