VARIATION IN LEPIDOPTERA A CRITICISM. 88 



has returned it to me as M. mniinnis var. warginicollis, Schil. My 

 specimen i^ a 3' • I append herewith a translation of Sel ilsky's 

 original description of this form : " The black colour in some examples 

 from Herzegovina (von Hopffgarten), and not rare there, extends 

 so that only the borders of the thorax remain yellow; in some 

 examples only the hind corners are yellow, whilst the arched side 

 portions of the thorax always remain yellow. The tibiae are then also 

 darker, and the first joint of the antennae alone remains yellow. In 

 this form, confusion with pi'lhiciilKs can easily take place " (Schilsky, 

 Deut. Knt. Zeit., 1892, p. 198). 



Variation in Lepidoptera — A Criticism. 



By J. W. TUTT, F.E S. 



We have before us the report of the Lancashire and Cheshire 

 Entomolog cal Society, for February 17th, in which it is stated that 

 Mr. W. M.msbridge read a paper entitled " Variation in Lepidop:era," 

 in which he " enumerated the different classes of variation as gi'uerally 

 undei'siood by lepidopterists, and referred especially to a phase of 

 variation which has not evoked the amount of interest its importance 

 warrants, viz., colour changes from yellow or ochreous to red or brown, 

 and modific iiiuns of these. The author considered these variations 

 as proceeding upon parallel lines to melanism, and probably arising in 

 a siniilar way, (1) by variation from a commonly occurring form in 

 the Darwinian sense, and ^2) by mutation or sadden leaps in the sense 

 enuncia.ted by De Vries." We had hoped that we could have passed 

 this report over as a poor or inaccurate summary by the secretary, but 

 as j\lr. Mimsbridge is secretary, and signs the report, one can only 

 assume the report is his own. 



We do not notice that Mr. jMansbridge makes any further refer- 

 ence of im[!ortance to the particular phase of variation that he 

 specially mentions, viz., from yellow or ochreous to red or biown, 

 and modifications of these, nor does he give any details refer- 

 ring to special species in wbicli these changes occur, nor discuss 

 the changes from an experimental point of view. Probably theie were 

 such in his extended paper, but this being so, a mere statement, in his 

 press reporr, that " this form of \ariat;oa has not evoked the amount 

 of interest that its imj)oriance warrants," appears to serve no useful 

 purpose, nor does Mr. Mansbridge's report suggest that he is aware 

 that considerable attention has been devoted to this phase of the 

 subject. It is now some sixteen years since we wrote, as an introduc- 

 tion to The BritisiL Xocttiae and tlieir Varieties, vol. ii., a comprehensive 

 chapter on " 'J'he Nature of Insect Colours, and their Genetic Sequence," 

 occupying no fewer than 16 clostdy printed demy 8vo. pages, of which 

 more than two-thirds are devotee! to the particular phase which, Mr. 

 Mansbndge suggests, has not received attention. Our thesis on the 

 genetic sequence of insect colours, among other things, dealt with two 

 presumaby progressive forms of development, viz., (1) through white, 

 yellow, orange, red, brown and black, (2) through white, yellow, green, 

 red (or brown), purple and black. 



'J'he subject is then considered in detail, illustrated entirely by 

 species that occur in Great Britain, and by facts that have been 

 accumulated by British lepidopterists. Probably Mr. Mansbridge 



