205 



The female of /'ii/'il: indeed, >ned) 



under three varieties, which iniini< vely thr<-<- entirely dU 



similar 5] ; .unl none of the I. 



male in coloration. 







The generally accepted explanation for t heSC remarkable hut nui, 



in which the female alone i> mimetic, i> that the female, bur- 

 dened with e.L^ r s and < on>e< |iient ly >lu.<^Mi in tli^ht and mm 1 



benefited hy imitating a >pc< ies whicli i.^ immune; while 

 the male li;is had no such incentive SO to -peak to he. oine min 



lUFSCj there ha> been no cons< ions evolution of mimi< 

 Wallace's fifth Stipulation is important., hut -hould read this way: 

 "The imitation, however minute, is but external and visible usually, 

 and never extends to internal characters which do not affect the exter- 

 nal appearance." For, as Poulton points out, the alertness of a beetle 

 which mimies a wasp, implies appropriate changes in the nervous and 

 ular systems. In its intent, however, Wallace's rule holds good, 

 and by disregarding it some writers strain the theory of mimicry be- 

 yond reasonable limits. Some have said, for example, 

 that the resemblance between caddis flies and moths 

 imicry; when the fact is that this resemblance 

 i merely superficial but is deep-seated; the entire ^ 



lization of Trichoptera shows that they are J \ 

 closely related to Lepidoptera. This likeness FlG - 249. A 



,1 . . , rr .. tettigoniid, Myrme- 



expresses, then, not mimicry, but affinity and cophana fall ax, 



parallel development. The same objection applies 



to the assumed cases of mimicry within the limits length. From 



r T r M i r TT T BRUNNER VON 



>mgle family, as between two genera of Hell- WATTENWYL. 

 coniidae or between the chrysomelid genera Lema 

 and Diabrotica. The more nearly two species are related to each other, 

 the more probable it becomes that their similarity is due not to mimi- 



but to their common ancestry. 

 On the other hand, the resemblance frequently occurs between 



ea of such different orders that it cannot be attributed to affinity. 

 Illustrations of this are the mimicry of the honey bee by the drone fly, 

 and the many other instances in which stinging Hymenoptera are 

 counterfeited by harmless tlies or beetles. A tettigoniid of the Sudan 

 hies an ant (Fig. 249), and the resemblance, by the way, is ob- 

 tained in a most remarkable manner. Upon the stout body of this 

 orthopteron the abdomen of an ant is delineated in black, the rest of 

 the body bein.u light in Color and inconspicuous by contrast with the 



