REFLECTIONS ON THE PHYLOUENETICS OF THE PYRAMEII) GROUP. Ill 



•of sporadic migration, but regular migration is a different thing. 

 What evidence have we of it ? 



We are told that I', kers/tani from Australia and New Zealand is the 

 atavic form, and again, that P. cari/e from South America is nearer the 

 generic prototype — which of the two are we to consider as nearer the 

 prototype, and is the assumption correct '? Ocellated spots are not 

 usually considered atavic — are they not an advance on the less intricate 

 pattern of the supposed generic prototype? Hence it follows that 

 blue pupilled eyespots are rather a recent acquisition than an atavism. 



It is interesting to note that the blue-centred spots in /'. canliti are 

 spreading all over America, well up north. I have specimens from 

 many parts of Canada, British Columbia, ^Manitoba, Montreal, and 

 •elsewhere, and we are not surprised when New Zealand specimens 

 show a similar line of development. There are evidently factors in 

 those parts of the world that are favourable to the evolution of this 

 feature, Avhich apparently do not obtain in the Elastern Hemisphere 

 generally. These blue ocellated specimens are stated in the paper we 

 are discussing to occur aoleh/ in the Sandwich Isles, but this is incor- 

 rect, both forms Hy there. 



It is of interest to remember that, in Madeira, where migration 

 scarcely comes in, no special form has developed. 1 say where migra- 

 tion scarcely comes in, my old friend, Mr. WoUaston, who lived there 

 for years, and was also constantly to and fro, never saw one of those 

 periodic migrations, and I had another entomological correspondent 

 there in recent years who never reported such an occurrence to me, 

 though we were constantly writing on kindred matters to each other. 

 This raises the point stated by Mr. Reuss that dark forms as from 

 Lapland are induced by cold, and light forms by heat. This I must 

 again query. I have a short series of ./'. canlni from the Island of 

 Nias, fine large specimens which are as dark as any examples I know 

 of, except possibly those small specimens where all the markings are 

 compressed into a very limited area — the fact is that moisture, possibly 

 in combination with other causes, induces darkness, and dryness 

 induces the light forms. 



Again, " P. vn/n'iina proves that the ataUoita -form tendency is 

 ^strongly inherent also in the rarihii-iovxn," but surely if, as is surmised, 

 both species (and I would say others too that I shall mention a little 

 later on) came from the same prototype, we should expect the same 

 tendency in all, the point that would be of special interest would be 

 the development of those species that had gone away from the original 

 stirps, and here I would suggest that an al)erration is an individual 

 Hying off at a tangent from the parent form rather than a "dependent." 



1 am rather at a loss to understand why Mr. lleuss places itra and 

 ijotwrilla in the same category — apart from the fact that the one occurs 

 in Australia and the other in New Zealand, and so to the man in the 

 street they ought to have something in common, I do not say they ought 

 to experts- — to my eyes they are as far apart, specifically, as two species 

 of the genus could be if Ave take colour and pattern as the standard, 

 and this is what Mr. Reuss is theorising on. This brings me to my last 

 point. Why have the species belonging to the Ethiopian region been left 

 out altogether ; ahi/aniuica for instance, or Itipjiotiwne .' The latter is most 

 important of all for it is tlw transitional species between /'. canlni and 

 /'. atalanta. It is true that it is placed now in the genus Ihijxinartia, it 



