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I learn from the writings of Mr. W. H. Edwards, that the name of that 

 butterfly is Chionobas Semidea (Say.) The description given by Mr. Scudder of its 

 terrible struggle for existence, tends to arouse one's interest in it, and draws out 

 one's sympathy for it, as we contemplate the dreary and joyless life it is doomed 

 to lead in its inclement home, so opposite to what is considered to be the typical 

 life of a butterfly. Grant Allen's conclusion is in perfect harmony with the 

 theories prevailing on this subject, but there is another view that can be taken of 

 it, which appears to me to be more in harmony with nature and observation, 

 although it may spoil the romance, and give less play to the imagination ; and 

 that is the one contained in the well-known principle of the power of environment 

 to modify the external appearance of living forms, and their ability to accommo- 

 date themselves to altered conditions. 



To illustrate the principle that I wish to apply in this case, I shall draw upon 

 Mr. Edwards's article on " Pieris Bryonise and its derivative forms," to be found in 

 Papilio, for June, 1881. He says : 



" The species, of which Bryonige is one of the forms, is known as Napi* 

 having in Europe three manifestations, Bryonias, Napi, and Napaese ; the last of 

 these was until recently regarded as a distinct species." Then quoting Dr. 

 Weisman who says of Bryonise : " This is to a certain extent the potential winter 

 form of Napi. This type Bryonise, in polar regions is the only form of 

 Napi. Bryonia produces but one generation a year, and must, then, 

 according to my theory, be regarded as the parent form of Napi." He then states 

 that in the Alps and Jura, Napi swarms everywhere, and crossing takes place, 

 which causes variability in Bryouise, but in Lapland Napi is never met with ; so 

 Bryoniae preserves its constancy, and concludes thus : " Pieris Bryoniae should be 

 elevated to the rank of a species, and ordinary winter and summer forms should 

 be designated varieties Napi andNapaeae." Then Mr. Edwards, after a description 

 of the markings of the various forms, says, " There are therefore the three forms 

 under which the species manifests itself in Europe, Bryoniae, Napi, Napaeae ; of 

 which Bryoniae may be considered the present form." Now to get myself into 

 harmony with nature, I have to reverse this order. We all know that 

 butterflies are lovers of the sun ; and that they are most numerous in kinds and 

 examples in warm countries where they flourish most luxuriantly, the conditions 

 being more congenial to them. Therefore the natural inference is, that butter- 

 flies would first appear on this scene of life, in localities that were most favourable 

 to them, and spread from these into tho^e that were less so. We are all familiar 

 with the restlessness of butterflies, and with what eagerness they will investi- 

 gate every spot, seemingly with a determination to establish themselves there if 

 possible ; they succeed if the conditions are at all favourable, and some of them 

 succeed even where the conditions are most unlikely. Now as Bryoniae is a darker 

 form than Napi, and* Napaeae being lighter still, and taking the result of Mr. 

 Edwards's experiments in this direction as a clue to some of nature's methods in 

 this matter, which goes to show that cold has the eflect of darkening the colour 

 of some kinds, I infer that Napaeae was the first to appear and to spread into a 

 localit}' with a cold winter. This acting on the chrysalides, Napi appears as the 

 spring form, and Napaeae as the summer one. As the distribution goes on it 

 reaches a yet colder climate, where Napaeae disappears and Bryoniae is the spring 

 form, with Napi as the summer one. Pushing yet onward it gets into a locality 

 where the season is too short for two broods, when the single brooded Arctic and 

 Alpine Bryoniae is alone to be found, and consequently constant, and there does 

 not seem to be the slightest reason to doubt, that if every Bryoniae was swept 

 out of Europe in one season, their place would soon be filled from the warmer 



