No. 605] 



ANIMAL COLORATION 



266 



mon flies and their primary and secondary parasites, and 

 more particularly by those of Forbes^'' andBryant^"^ upon 

 the feeding habits of birds. 



In his paper, which has been cited above, Dixey was not 

 discussing the validity of the mimicry hypotheses and 

 has not attempted to explain what limits the numbers of a 

 mimic in proportion to those of its model. Wallace also 

 failed to elucidate the mystery, leaving his readers to find 

 the way out of their difficulty as they might best be able. 

 Search elsewhere for helpful suggestion in the matter 

 yields little of value. Poulton^^ holds that ichneumon flies 

 are particular enemies of the larvse of "protected" Lepi- 

 doptera, but this idea need not be taken very seriously at 

 present, for it is apparently based upon the oltservation 

 of a high proportion of parasitized iiidiv'Hhuil^ among 

 such forms rather than upon comparati\ i' stali>i l('- cox or- 

 ing "unprotected" species as well. hWon it ii were li ne, 

 while it w.ml.l bolster tlu" xxarninu volui li\ potiu ^i^, it 

 w.uiin aumaxat. llic situation vt-anliim r>ati-ian niini- 

 i.-i>. Tlu^icroi,' nnh nuv r..ncln^ion i^ po^^il.K-: Tlie 

 tlu'oivtical (>hi(M-ti.ui~~ tlicv \hvuiMvv> have rai.M.l are 

 not adi.inalclv ni,-t hv -.pokrHucn for the two hvpotlieses. 



AVhat (.hM.nr.i la.-N Mipp-it the <.ontcntioii that many 

 animals aiv ma.U' .M.iispi.-iK.ii:^ and pi'olit l.y the striking 

 combinations of coh)r tliey disphav. >li()nhl next ho deter- 

 mined. 



in 18G7 Wallace22 suggested hid'ore l-hitomologieal 

 Society of London tliat. as a rnh'. hi illiantly e(>h)red larvfE 

 are distasteful to hifds. expre»(Ml his desire for infor- 

 mation and his - ratilieation. it' aii\- who kept l)irds, par- 

 ticularly indiuiMioiis species, wonld inak(> experiments 

 with different larvtp to ascertain wliicli were eaten and 

 which rejected. Members of the society and others have 

 repeatedly acted upon his suggestion and commonly 



