24 BRITISH BUTTERFLIES. 



one took one direction, and another another direction, can only have 

 resulted from the particular method adopted being a line of evolution 

 easy or convenient to some ancestor. 



In comparing the Melitaeid gregarious larval habit with that of the 

 Vanessids, one appears to get a clue that, whilst the larvae of both use the 

 silken web for a carpet, in order to obtain a safe footing, the accumulative 

 result in the one case is for hiding and hybernation purposes, and the 

 other for protection by means of the warning and distasteful properties, 

 the larvae freely exposing themselves. This lies in the fact that, whilst 

 the Vanessid larvae are largely inedible, those of the Melitaeids are 

 much less so, and may even be palatable, for, whilst the Vanessid 

 larvae develop marked warning colours, those of the Melitaeas, especially 

 as they reach adult age, are often particularly cryptic. Still, this view 

 cannot be carried too far, as the larvae of Aglais urticae do a consider- 

 able amount of spinning for hiding purposes, after the social nest has 

 been deserted, and, on the other hand, the larvae of Euphydryas phaeton 

 are noted by Scudder as being usually, after hybernation, exposed to 

 view, when their brilliant colours and active movements make them 

 very conspicuous. 



The gregarious habit, as we have already pointed out, must be con- 

 sidered as a purely modern development, a habit that has been adopted 

 and dropped over and over again, and not one retained by the present 

 gregarious species from remote ancestors. It would be absurd, for 

 example, to suppose that gregarious Nymphalids (Melitaea, Vanessa, 

 Chlorippe, etc.) are descended from gregarious Pierids (Aporia, 

 Pieris, Eueheira, etc.), or vice versa, and the non-gregarious Nym- 

 phalids (Argynnis, Apatura, etc.) from non-gregarious Pierids, or vice 

 versa, although one may safely assume a common origin for the 

 gregarious Melitaeas at a comparatively recent date, and similarly for 

 the gregarious Vanessids, or Pierids, etc. Nymphalids arose together, 

 and in the mass are solitary, and so, most probably, was the original 

 ancestor. Similarly, the Pierids are, in the mass, solitary, and had a 

 solitary ancestor, and so on, each of the gregarious groups having 

 arisen long after by itself, within its own superfamily group. 



CHAPTER III. 



FAMILY HABITS IN BUTTERFLY LARV.E THE VANESSIDS. 



It will be within the knowledge of most lepidopterists that there is 

 considerable resemblance in what one may term the family habits of 

 butterfly larvae, and yet, when one considers the available facts, in detail, 

 it will be at once observed that there are sometimes very great differences 

 in the habits of the larvae of what are evidently closely allied species. 

 Thus, in a general way, the idea is prevalent that the Vanessids have 

 gregarious summer-feeding larvae ; that the Melitaeids have gregarious 

 larvae living from autumn to spring, with a long hybernating period, in 

 which they are closely packed 091 masse in their hybernacula; similarly, 



