1889.] 197 



But to come to Mr. Barrett's own experience. He says that " he 

 reared a considerable number some years ago from Surrey larvse, of 

 which he still has about a dozen. Of these dozen, ' most ' (that is 10) 

 ' are of the full size ; one hardly larger ' (but still larger) ' than the 

 Scotch form ; and one intermediate.' " Is this percentage of smaller 

 forms an unusual one ? Is it sufficient to warrant Mr. Barrett in 

 saying further on " it appears that these forms from Surrey are variable 

 in size?" Of 13 turionella (all bred) in my own cabinet, only one (a 

 <$ ) bred last year from a separate locality, is below (and not much 

 below) the average size ; and certainly a comparison of the series of 

 turionella seen in other collections does not induce me to consider it 

 a species given to vary from its average size, at least, never down to 

 half its size, which is the expanse of wings assigned by Mr. Barrett 

 himself to the Scotch form. 



Of all these forms examined by Mr. Barrett, numbering I may 

 take it as many as two dozen, all but one were only half the size of 

 turionella, and that one, to the best of Mr. Barretfs recollection, a very 

 curious one, different from any others he has seen, and as large as 

 turionella itself! Now, for the purpose of my argument, I am not 

 bound, I think, to include this specimen (not bred, curious in appear- 

 ance*) among the rest ; but, supposing it included, the fact still remains, 

 that on the average the examples of the Scotch form are, in point of 

 size, no more variable than, nor even half so variable as, the southern 

 form. But Mr. Barrett says " they are fairly constant in their small 

 size." He has only, by his own confession, seen one big one. 



Next, as to the extent of the rusty coloration of the fore-wing, I 

 cannot agree with my friend's conclusions. Of the thirteen specimens 

 before me, all but one, the above-mentioned ^ of last year's breeding, 

 have more or less of the rusty tinge up to the base, certainly always 

 over the full apical half, of the wing, so that it is not correct to say 

 that the southern form is variable in colour ; by far the greater pro- 

 portion of examples are rust-coloured — why else does the imago seek 

 protection by resting on the brown buds ? The forms in which the 

 rust colour is confined to the apex, or apical half, as in Mr. Barrett's 

 two Lynn specimens, and in my single <$ , are exceptions to the average 

 coloration. On the other hand the Scotch forms never show any rust 

 colour beyond just the apical third, none at least that I have seen ; 

 indeed, if the two species are inspected at a distance of a yard or so, 

 the contrast between the rusty-coloured turionella and the rusty-tipped 

 posticana, with its dark basal two-thirds, is singularly striking. 



Next, let us take the hind-wings of the two forms. Mr. Barrett 



