REVERSION OF ARCTIC EREBIA LIGEA, ETC. 



35 



They were placed upon grass immediately, and commenced 

 laying ; the ova were kept out of doors, and the larvae emerged 

 in the February of 1911, being half-grown at the end of June, 

 when they proceeded to ^stivate. Reappearing at the end of 

 August, they fed up and pupated, being now kept in a warm 

 room. The first imago appeared on October 12th, the last on' 

 December 31st. 



The larvae differed considerably in appearance from_ the 

 ordinary form of Harz ligea, being darker and plainly striped. 

 In nature ligea ova He over the winter, and Herr Selzer says 

 that " the larvae which emerge in the spring hibernate the 

 winter following," an imago rarely occurring late in the 

 summer ; so that the life-cycle of the typical ligea of the Harz 

 extends apparently through two years. 



A comparison of adijte imagines from the Engadine and from 

 Zermatt showed them to be identical with the Lapland form. 

 Those in my own collection do not differ materially from 

 examples from Cortina, the Brenner, &c., and, as I said before 

 {loc. cit.) of the Abisko specimens, the superficial differences 

 from the type are not marked in the male to any great degree. 

 But those bred from Herr Selzer's Abisko ova were absolutely 

 identical with the E. ligea from the Harz Mountains. Mr. 

 Carter kindly sent me also a photograph illustrating in detail 

 the results of this experiment, but, unfortunately, I am unable 

 to reproduce it in this Journal, owing to the size of the block. 

 It would be interesting to discover how far Lapland adyte, bred 

 under natural conditions in Hamburg, would approximate to the 

 type. But, as Herr Selzer claims, the contention as regards the 

 specific identity of adyte and ligea may now be considered settled. 



As throwing further light on the subject of type reversion, 

 Herr Selzer proceeds to record his experiences with Pararge 

 mcera var. adrasta. From females of this variety captured at 

 Zermatt, sent to Hamburg for the purpose, ova were obtained, 

 the larvae still differing slightly from Harz typical form. But 

 no difference was observable between the resulting imagines and 

 the typical form. So that it may be inferred that the change 

 back, due no doubt to altered conditions of climate and tempe- 

 rature, comes about in the pupal phase principally, as has been 

 demonstrated, I think, by the experiments of Mr. Merrifield 

 and others. 



Two further notes by the same author, communicated to the 

 ' Internationalen Entomologischen Zeitschrift ' (No. 42, Jan. 

 18th, 1913, p. 293) on the subject of hibernation are also 

 exceptionally interesting to British lepidopterists. Herr Selzer 

 says that he found a freshly emerged Pyrameis atalanta at 

 Heiligenhafen, on the Baltic, in the early part of June, and 

 regarding this as an indication that the butterfly passes the 

 winter in the pupal phase, he searched the same spot later in 



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