( 4 ) 



settling on her wings, though he still continued flutter- 

 ing while touching her. He eventually became alarmed at my 

 presence and flew away. Dec. 29, 1911." 



[vii 



"The .Study of Mimicry (Batesian and Miillerian) by 

 Temperature Experiments on two Tropical Butterflies," by 

 Lieut. -Col. N. Manders, R.A.M.C., F.X.S., F.E.S. 



A long and important discussi< >n arose on many points in con- 

 nection with the last paper, of which a full report is appended. 



Prof. PODLTON said that Col. Manders was much to be 

 congratulated on t he positive results that he had obtained 

 in botli D. chrysippus and //. misippus, female. Furthermore 

 the indication that the female of D. chrysippw was more 

 sensitive than the male was of t lie highest interest. When 

 Col. Maulers firsl expressed the intention of making these 

 experiments the Bpeaker thought they were rather in the 

 nature of "a forlorn hope" and the results were as surprising 

 to him as they were interesting. He felt that Col. Manders 

 had made out a case for reconsidering the conclusion (which 

 Prof. Poulton had published in Tian-. Hut. Boc. 1902, pp. 

 •175-0, 482 1) that the type form of chrysippus was older 

 than the doripptu form. The reasons for this conclusion still 

 appeared to him to be strong as well as numerous, but the 

 whole Bubjecl required to be reinvestigated in the light of 

 t bese n. -w results. 



When we compared chrysipptu with its form dorippus and 

 the female misippus with the form inaria, it was quite clear that 

 both forms differ from their types by the omission of a part of 

 the pattern, and in no other way. Hence the type should be 

 a Mendelian dominant in l.oth species, as Rev. K. St. Aubyn 

 Rogers had shown to be probably the ease in //. misippus 

 (Proc. I'm. Boc., 1911, p. xliv). But Mendelian dominance 

 did not help towards the phylogenetic solution; for, accept- 

 ing the generally received " presence or absence" hypothesis, 

 it was obvious that a newer form may arise from an older by 

 the addition (= dominance) or the omission (= recessivit y) of 

 a factor.* 



* Bateson, " MendeTa Principle* of Heredity," Cambridge, 1909, p. 278. 



