LTXN'EAX SOCIETY OF LOXDOX. 47 



nil aggregate of individuals of arthemis ought to show a tendency 

 in that direction bv virtue of the fact that by hypothesis tlie 

 sHi-vivinr/ adults would be those whose resembhince to the immune 

 Anosia lias been the means of their preservation from destruction " 

 (p. l^OS). 



I regard this inference as quite unsound. I do not believe that 

 the presence of the Danaine model, plexijiims, has the sliglitest 

 effect upon the pattern of Limenitis arthemis. A colour variation 

 siitlicient to cause the one butterfly to be mistaken for the other 

 at any rate under certain circumstances of movement, or distance, 

 or h'ght and shade, &c., must have jireceded the evolution of the 

 luiiiietic pattern as we now see it. If I had thought it possible 

 tliat such an inference would have been drawn, the present 

 statement would have found a place in the original paper. 



Professor Abbott furtliermore infers that 1 coiiunitted myself 

 to the beHef that the evoliilion of various elements in the mimetic 

 pattern was simultaneous * (p. 215). I did not intend to express 

 any such helieF : I do not hold it. The 1908 paper criticised by 

 him was concerned with an analysis of the fully-formed mimetic 

 pattern of L. arclnppus and the identificatiun of the modilied 

 ancestral elements in it — not, except in the most general \vay, 

 with the sequence or simultaneity of their evolution. I regarded 

 this as a far more speculative matter, perhaps incapable of 

 solution, at any rate not the subject in hand. 



Professor Abbott's measurements of colour elements in the 

 ])attern of Limenitis arthemis, interesting and \aluahle as they 

 ai-e in themsel\es, do not affect my conclusions. Pie finds no 

 evidence of " selection with reference to the mimetic colours " 

 (p. 1220) of this non-mimetic species, and I should expect none. 

 1 admit that Scudder's statement t quoted by Professor Abbott 

 (p. 204, n. 3) does suggest that the mimicry started in small 

 variations of the orange or red elements in tlie pattern, but even 

 here .there is no suggestion of simultaneous evolution in the 

 other elements. I freely admit too that my own statement + was 

 open to Pi'ofessor Abbott's interpretation as regards the reddish 

 elements, and these alone, — the very elements which he liiids to 



* Note also the following passnge on pp. iil7, 218: — "On llie bnsis of 

 7'rofessor Poiilton's hypothesis we shoiilcl expect not only tliat a selective 

 iiilluence sliould be evident both in the reduction of the wbite band and tlie 

 extension of the red pati-b, but also that the majority of the surviving 

 individuals \oi arthemis\ should combine these effects.'' 



t -'Individuals among the normal species vary somewhat in this particular, 

 so that it is easy to suppose that some of ijje original «;Y7?/)yj«.s with nuire 

 orange than usual may have escaoed capture on occasion i'roui this cause, 

 i'^rom such a small beginning such as one may now see every year in 

 U. asti/cniax sprang doubtless the whole story. . . ." Scud('er's statement seems 

 to me to imply that the reddish elemenis enlarged first while the other changes 

 followed later. I admit that I have never seen an asfyaiia.v with the reddish 

 tint so extended as to suggest a probable first step towards the mimetic like- 

 Tiess, but my experience is of course very small (compared with Scudder's. 



X " Tlie cliaracter in flr//«;«(2s which initiated tJie mimicry of ^Hwm is the 

 subinarginal row of reddish spots, conmioiily found in the hind wing, more 

 rarely in the tore" (1908 paper, p. Ai^Q). 



