on MiiUerian Mimicry and Diaposematism, 573 



diaposematic interpretation of certain concrete and definite 

 instances. 



With regard to these instances, I would in the first place 

 observe that they are not all of equal strength, and tliat, 

 as I have always been ready to admit, there is perhaps not 

 one of them that is absolutely incapable of being explained 

 on other lines. But their force, as it seems to me, lies in 

 their cumulative effect. Let me give an illustration. 

 Suppose that on a riding or driving tour through the 

 country, you see, on approaching a town, a boy wearing a 

 straw hat with a variegated ribbon. By and by you meet 

 with another boy, then with two or three more, finally 

 perhaps with a little crowd of boys, all with the same 

 coloured hat-ribbon. The first occurrence makes no special 

 impression on you, nor perhaps the second or third, but 

 before long you awake to the fact that there must be some 

 common cause for this constantly recurring phenomenon, 

 which cause will probably declare itself as the existence of 

 a school or an athletic club. So with these instances of 

 apparent intercbange. Taken separately, each one may 

 be put down to accident, coincidence, affinity, or what you 

 will ; but as cases begin to accumulate, any explanation 

 short of the influence of some common law or principle 

 ceases to be satisfactory. With respect to Mr. Marshall's 

 remark that no example of Diaposematism has as yet been 

 brought forward as occurring between any two of certain 

 groups that he specifies, it may be sufficient to observe 

 that these groups, so far as I am aware, have never yet 

 been studied from this particular point of view.* 



The Association of Pereute and Heliconius. 



Under this head I am pleased to find that Mr. Marshall 

 at least agrees with me that there is a mimetic relation 

 between the meljJo^nene group of Helicmiius and a FcrmiU, 

 though Mr. Kaye would perhaps differ from us both (see 

 his communication in Proc. Ent. Soc. Lond., 1908, pp. xxii, 

 xxiii). But Mr. Marshall, in commenting on my sugges- 

 tion that the Heliconii which enter into mimetic combina- 

 tion with Pierines have been influenced by the latter " in 

 adopting from them a more distinct and characteristic em- 

 ployment of the red basal patches," remarks that " in order 



* See however Fritz Miiller (translation by Meldola in Proc. Ent. 

 Soc. Lond., 1879, p. xxviii), who actually alleges cases, though with- 

 out giving details. 



