SKASDNAI. VAUIATIOXS OF PARARGE AiEGEUA, 



209 



On the Geographical and Seasonal Variations of Pararge megera, L. 



By liOGER VERITY, M.D. 



Tbis species had for the last few yeai's baffled my attempts to define 

 its geographical and seasonal variations, although I felt that definite 

 characteristics of races and generations did exist. They are, however, 

 so subtle and so overshadowed by the very much more striking indi- 

 vidual variations, which occur in all localities and at all seasons, that 

 for a long time I could not grasp them. Oberthiir seems to have had 

 the same impression, because in his Etiidi^s de Lep. Coiuji., III., p. 364, 

 he mentions several geographical variations, but he concludes that races 

 cannot be separated distinctly, except in the case of tijfiiliiin. I went 

 on collecting series from all sorts of regions, although I found con- 

 siderable difficulty, because correspondents do not realise that the most 

 widespread and abundant species are the most interesting m the study 

 of variation, and they seem to think they are not worth procuring. I 

 think I have at last detected the lines of variation produced by sur- 

 roundings. They are subtle, as I say, but, as they exist, this is no 

 reason for neglecting them niore than characters, which are striking at 

 first sight, and which any untrained eye can perceive. In most cases 

 they are not absolute and constant, individual exceptions occurring, 

 but the percentage of the latter is sufficiently small to be considered as 

 su;:h, and for the existence of a general rule to be established just as 

 much as in most other species, in which it is more easily seen. 



A greater or lesser degree of variation along the following lines 

 xiistinguishes the summer generations from the first one in all regions, 

 slight as it may be at times; the same variation takes place in the 

 summer generations, as one proceeds from colder and damper surround- 

 ings to warmer and drier ones, and finally it is also found in the first 

 generation, when one passes from the remainder of Europe to its 

 Bouth-Eastern portion : the wings become narrower and more pointed 

 at apex ; the androconial scales are seen microscopically to become 

 more slender at their further end ; the fulvous colour above becomes 

 warmer in tone a.nd brighter ; the upporside dark markings become 

 less extensive in general and the basal patch of the hindwings gets 

 invaded by fulvous and, in consequence, lighter in tone, whilst the pale 

 shaded band which precedes the ocellated spots tends to obliteration ; on 

 the underside of the hindwings spaces of the clear ground colour appear, 

 especially round the ocellated spots and along the dark streaks, and 

 they break up the diffused scaling into bands and patches, so 

 that these and the streaks stand out boldly, and give a more 

 variegated appearance to the entire wing, increased by the fact that the 

 streaks become darker and sharper (especially the lunules between tbe 

 ocelli and the margin) ; these spaces increase in extent, as the diffused 

 sealing withdraws, till the latter disappears entirely ; the ocellated 

 spots, however, remarkably enough, tend to become larger, especially on 

 account of the two streaks, which encircle them, becoming broader and 

 of the inner one becoming more distinct. It must be noted that other 

 individual variations found in all localities and seasons are distinctly 

 greater in the fenrale sex, but that the variations described above, which 

 characterise the average of series from different regions and seasons, are 

 on the contrary more marked and distinct in the male. The main line 

 of variation of the species consists decidedly in that afforded by the 

 December 15th, 1922. 



