1036 TIIK BUTTERFLIES OF NEW ENGLAND. 



Wallace, who has given this group particular attention, gives us the 

 following picture (loc. cit.) : — 



The wliite or yellow colour that characterizes these familiar insects is that which re- 

 curs most frequently tlirougliout this group in every country ; but in the tropics other 

 forms appear by tlicir side decorated with a variety of colours and assuming to some 

 extent the forms and markings of the more brilliant families of butterflies. It is to 

 be observed, liowever, that in most cases the ground colour of the insect is either white, 

 yellow or black, and even in those exceptional cases in which the wings are entirely 

 red or l)luish gray, the female of the same species, or of one closelj' allied to it, pre- 

 sents us with tlie usual simple coloui's. The rich rufous brown, which so constantly 

 reappears tliroughout the great family of the Nymphalidae, is not to be met with in a 

 single instance in the whole range of the present family. The metallic blue of Morpho 

 and of the Lycaenidae, and the ricli green of various sliades which occurs in most 

 other groups of butterflies are also entirely absent. Although the markings are often 

 very beautiful and very varied, well-formed ocellated spots (almost universal in the 

 Satyridae and very frequent in the Nymphalidae) never once occur; the only approach 

 to them being the small discoidal ocelli in some species. The form of the wings is 

 generally rounded, rarely angular, and the hind wings are never adorned with spatu- 

 late, linear or (iliform processes, such as occur frequently in most other groups of 

 butterflies. . . . 



It appears, then, that quite independently of structural cliaracter, the I'ieridae pos- 

 sess specialities of colour, of marking, and of form of wing, which in their combinations 

 mark them out as a natural and somewhat isolated group ; and strikingly illustrate 

 the stability of type that sometimes obtains in what we usually deem unimportant 

 and very variable characters. At the same time it is to be noted that in the important 

 structural character of the neuration of the wings, few families exhibit so many modi- 

 fications. . . . The form and texture of the wings also seem very subject to modittcation 

 within certain limits, as is well seen by comparing the delicate, elongate forms of 

 Leptalis and Leucophasia with the strong and compact Callidi-yas and Colias; and in 

 colouration no contrast can be greater than tliat between such genera as Euterpe and 

 Gonepteryx. Perhaps, too, there is no family more generally and uniformly distributed 

 over the whole earth. Pieridae inhabit tlie deserts of Arabia as well as the tropical 

 forests ; they sport about the snows of the Himalayas and roam over the icy plains of 

 Siberia. The variety of conditions to which they are subject is therefore as great as 

 can well be conceived, and the considerable generic diversity that exists among them 

 probably indicates a great antiquity for the group, yet the ever fluctu.ating characters 

 of colour, form and marking have nevertheless their strict limits whicli they In no case 

 overpass. 



"They are very pretty, graceful butteriiies, says Trimen, "with a 

 tolerably swift, irregular flight. They seldom rise to any height and settle 

 very frequently on flowers." The tropical species, however, fly higher, 

 "now on the tops of the trees, now down near the ground" (Collingwood), 

 though they have apparently the same swift yet uncertain flight most re- 

 sembling that of their brethren the Papilioninae. Above all other butter- 

 flies they show a fondness for simple moisture, the males particidarly 

 collecting in amazing numbers on the margins of pools and streams. Two 

 accounts of this quoted by Distant from others I am impelled to repeat 

 here. The first is the experience of an entomologist, M. C. Piepers in 

 Celebes : — 



My companion suddenly exclaimed, as we wei'c crossing a nearly dry brook, "Oh, 

 look what a beautiful (lower I" And on looking where he pointed I saw in the bed of 



