significance of wing -markings. 91 



previously directed by Darwin* and Lubbock, f has 

 been fully treated of with great completeness of illustra- 

 tion by Weismann, in his essay on ' Phyletic Parallelism 

 in Metamorphic Species, I where he has shown this want 

 of congruence between larval and imaginal affinities to 

 be especially well-marked among certain of the sub- 

 groups of the family now before us. In cases where the 

 form-relationship of the larvas does not coincide with 

 that of the imagines we may find it difficult to determine 

 which of the two is the more trustworthy guide to the 

 real affinities of the species ; but where the evidence 

 from both sides can be shown to point in the same direc- 

 tion such grounds of doubt no longer exist, and we may 

 claim to have gone far towards establishing the true 

 phylogenetic relation. It is interesting therefore to find, 

 as will appear before the end of this paper, that Miiller's 

 conclusions, as far as they go, and when due allowance 

 is made for the facts just referred to, are in general 

 accordance with the results to which I have been led by 

 an entirely distinct method of investigation. 



As a preliminary to the minute comparative study of 

 the wing-markings, it will be well to lay down certain 

 landmarks to serve collectively as a sketch outline of 

 which the details may be afterwards filled in. For this 

 purpose let us first of all glance at the costal margin of 

 the fore wing in V. urticce (fig. 1). Here occur three 

 dark patches alternating with four areas of lighter 

 ground colour, the innermost of which is red, the next 

 two yellow, and the outermost white. These three dark 

 patches I distinguish by the Eoman numerals L, II., III., 

 in order from within outwards ; while to the four light 

 coloured areas I give in similar order the letters A, B, 

 C, D. Outside the white patch D comes the dark sub- 

 marginal band. This I regard as in series with the 

 costal patches, and accordingly recognise it as IV. Now 

 these eight costal areas of alternate light and dark 

 colour will be found in one form or another in most of 

 the insects with which we shall have to deal ; and I 



* « Origin of Species,' p. 440 (1st Edition). 



f ' Origin and Metamorphoses of Insects,' 1874 ; vid. esp. pp. 

 89, 70. 



I ' Studies in the Theory of Descent,' English Edition by Prof. 

 Meldola, 1882, vol. i. p.390— vol. ii., p. 554. 



