210 



[August, 



tbougli its food-plant grows here more or less plentifully in all the 

 woods, I can only find the insect in one small corner of one of them. 

 In this very limited spot it is fairly common, nearly every bush having 

 a few tenanted leaves, with occasionally two or even three mines in 

 a leaf. 



Tarringtoii, Ledbury : 



July 10th, 1890. 



THE aENUS SCOPARIA. 

 BY EUSTACE R. BANKES, M.A., E.ES. 



With reference to the question of S. amhif/ualis and atomalis, the 

 difference between Mr. C. A. Briggs and myself as to what constitutes 

 " proof " seems to have been caused by Mr. Briggs having suddenly 

 changed his ideas on the subject ; for, after stating in Entom., xxii, 

 p. 16, that, "if entomologists working near the junction of the High- 

 lands and Lowlands would hut collect these species for comparison, the 

 MATTEH WOULD SPEEDILY BE SETTLED," he now cxpresscs doubts as 

 to whether the question can be settled " satisfactorily or otherwise " 

 by a study of the appearance of the insects themselves ! To my 

 mind, however, the evidence furnished by the appearance of a long 

 series, showing every poPoihle intermediate form, is amply sufficient for 

 sinking atomalis as merely a variety of amhicjiialis. Species (as they 

 have once been considered) are being continually relegated to the rank 

 of varieties on precisely the same amount of evidence, if no good reason 

 for retaining them can he shown ; and though it would be very inter- 

 esting to " breed from the egg," I doubt whether it would be considered 

 at all necessary by a jury of practical entomologists with all the 

 evidence before them. Unless we have about a dozen different species 

 confused together as one, some out of a number of bred atomalis would 

 be quite certain to " approach amhigualis, and vice versa" else how can 

 the existence of the whole range of exactly intermediate forms be 

 accounted for ? 



It would appear from his statement on p. 124, lines 6 — 11, as 

 though Mr. Briggs had written his note in Entom., xxii, p. 16, after he 

 had compared a large number of specimens in January, 1SS9 ; but 

 this clearly cannot have been the case, as his note in Entom. is dated 

 December 10th, 1888, and was published in the Magazine /or January. 



In the matter of 8. mercurella and cratcegella, Mr. Briggs is 

 astonished that I should " confess " that the easiest way to pick out 

 the two species from a mixed series is by the eye ! But, surely, the 

 quickest way in such a case is naturally the easiest, and I neither 

 stated nor implied that it w^as the surest or the only way; — far from it ! 



