IN TUB BRITISH ISLANDS. 27 



tinct, and must be so recorded." But, subsequently, in writing of 

 capsophila to Mr. Newman, Mr. Birchall adds : " This insect is the 

 Irish representative of I), carpophaga, and in my opinion only a variety 

 of that species, and reaches its extreme point of divergence from the 

 English and Continental type in the Isle of Man. The difference be- 

 tween capsophila and carpophaga is wholly one of colour, and only 

 exists in the perfect insect, the caterpillars and chrysalides presenting 

 no difference. As we travel northward in Great Britain, there is a 

 gradual deepening of the shade of colour from the clay-coloured, 

 almost immaculate carpophaga of the southern counties, to the rich 

 brown specimens obtained in Argyleshire. Amongst the Irish capso- 

 phila an occasional dark brown specimen occurs, but the colour of the 

 majority is dark grey.* The Manx specimens are usually still darker, 

 sometimes almost entirely black. The explanation seems to be that 

 the species has reached Ireland by way of Scotland, and that the effect 

 of insular conditions has been still further to increase the divergence 

 from the original type of the mainland. As regards its natural history, 

 the Isle of Man is certainly an outlying province of Ireland, in many 

 respects " Hibernior Hibernicis." Capsophila occurs on the Irish coast 

 from Belfast to Waterford, but I have not seen or heard of it on the 

 western coast, or in the interior of Ireland. There have been records 

 of its capture in North Wales, but I have not seen the specimens, and 

 cannot say whether they ought to be referred to carpophaga Or capso- 

 phila. This species was first discovered by Anderegg, in Switzerland. 

 Guene'e gives 'Alps of the Valais, neighbourhood of Digne,' and 

 ' Spain,' as the Continental habitats ; and he describes the Spanish 

 form as " much darker than the Swiss, and almost black, with the 

 transverse lines very white and slender, the wing-rays powdered with 

 white, and the underside very dark." Mr. Newman adds: "This 

 seems to militate against the opinion expressed above by Mr. Birchall ; 

 and it is a remarkable fact that the most northern and most southern 

 examples of the species are the darkest " ( British Moths,' pp. 386-387). 

 Twenty years ago very little was known of variation, and 1 feel satisfied 

 that capsophila is as well developed a species as many other so-called 

 species in our lists. The knowledge that we now have of parallel 

 variation, and the tendency of species to copy, in their varieties, the 

 normal markings of allied species in the same genera, and at the same 

 time, the similar facies developed in moths, most dissimilar in structure, 

 when placed under similar circumstances or natural conditions, should 

 check us from laying too much stress on purely superficial characters. 

 It is remarkable that Duponchel figures a brown form as the type, in 

 no way so dark as our specimens, whilst Guenee gives quite a satisfac- 

 tory description of our typical form under his var. A. Mr. W. H. 

 Blandford very recently brought the subject to the front (' Ent. Mo. 

 Mag.,' vol. xxvi., p. 8U), due to breeding imagines of both species 

 from Iarva3 taken at Tenby. So good a lepidopterist as Mr. C. G. 

 Barrett seems inclined to agree with him as to the specific identity of 

 the two forms, but adds : " The two forms are to be definitely dis- 

 tinguished." Most certainly they are ; and it must be remembered 



* I cannot see any difference whatever in the specimens in my cabinet which 

 have come from Ireland and the Isle of Man. Grey specimens occur in both, 

 and these come near D. earpopha0a var. fusca-pallida. 



