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secondary black spot appears, which, in one instance, is almost joined 

 up to the central spot. This secondary spot also appears in several 

 of the spring males from Cornwall. 



The costal spot on the hind-wings is also larger and blacker in the 

 summer form than in the spring form in both sexes. The upper 

 surface of the spring females is, generally speaking, greyer, the apical 

 tips and the spots are less black, and the grey scaling more extended 

 over the wings than in the summer form. In the latter the contrast 

 between the black spots and the ground colour is decidedly greater. 

 In both forms occasionally there are black scales between the central 

 and lower spots, and more rarely between the central spot and the 

 apical blotch. 



In the females of the summer form we sometimes, but not com- 

 monly, find a black central spot in the hind-wings, and more rarely 

 a faint indication of this in the spring form. We have also a faint 

 indication of this in an Irish male of the summer form. 



As regards the under-surfaces, in both sexes in the summer form 

 the black spots are larger and blacker, the ground colour is yellower 

 and the veins of the hind-wings have less dark scaling, than in the 

 spring form. 



These remarks refer to the general characteristics of the species as 

 I know it. Mr. Harrison when exhibiting our series will point out 

 some of the more unusual variations we have met with. 



Besides the British specimens which we have bred we have also 

 the various broods of the Alpine variety bryo?iice^ which we exhibited 

 at our last meeting. This, occurring up to the snow-line in the Alps, 

 is single brooded. In the males the central spot is occasionally 

 developed, but more usually it is absent, the veins on the under- 

 surface of the hind- wings are generally heavily scaled, as in our spring 

 form, but in some specimens certain of the veins are almost bare of 

 dark scales. Variation in this respect seems to be decidedly greater 

 than in our British forms. 



In the females variation is also very great. The ground colour 

 ranges from a bright yellow to a whitish grey. The black spots vary 

 in size and intensity of colour ; in some being small and faint and of 

 the same dull grey colour as the general surface of the wings, in 

 others being extremely large and black, with every gradation between 

 these extremes. 



Reverting to our British napi, Mr. Hawes stated in May, 1892, 

 that from ova obtained from a female in June, 1891, he bred 45 

 butterflies, 14 (or 31 per cent.) of which emerged in June, 1891, and 

 the remaining 31 (or 69 per cent.) in May, 1892. He notes that 

 1 89 1 was a cold season. 



Later workers have found that from 50 to 60 per cent, of the pro- 

 geny of the spring specimens usually emerge in the same year, and 

 40 to 50 per cent, lie over till the following spring. There is, how- 

 ever, great irregularity in these proportions. Mr. H. Williams, in 

 May, 1894, exhibited a series of this insect, the progeny of two 



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