Mimetic Patterns to the Original Form. 75 



The same argument will apply to features similar to 

 the above which may be seen in certain Papilioninpe., 

 Nymphaliufe, Erycinidie, and even in some moths. 

 And I may say in passing- that Fritx Miiller's principle 

 here referred to appears to me to be of much wider 

 application than has been hitherto supposed. There 

 exist several large groups more or less uniform in their 

 scheme of coloration, though heterogeneous in their 

 affinities, which it seems almost certain will in the main 

 turn out to be cases of "inedible associations,'' each 

 one possibly including a few instances of true mimicry 

 within its borders. In deciding on the actual nature 

 of such resemblances, it may be borne in mind that 

 "reciprocal mimicry " constitutes good evidence of the 

 distastefulness of all the forms between which it can be 

 shown to occur, while the abundance or scarcity of a 

 mimetic insect is also a valuable test of its edibilitv. 



IV. Divergent Members of an Inedible Group. 



The last set of figures (PI. V,, Figs. 1 5-1 8) discloses a re- 

 markable state of things, which is of interest both in its 

 bearing on what has been advanced in the preceding sec- 

 tion, and also as providing a further illustration of the im- 

 portance of small changes. The Pcvpilio represented in 

 Fig. 15 (P. zacynthus ? ) is undoubtedly the model for the 

 Pieiine shown in Fig. 16 (E. tereas). These two insects 

 form one of Bates's original instances of mimicry. But 

 beside the latter we have another Euterpe, viz., E. hellona 

 (Fig. 17), whose markings are, without doubt, homologous 

 with those of its congener. E. hellona however, though 

 so closely resembling E. tereas the mimic of P. zacynthus, 

 itself copies, not the Pajxilio, but the members of a group 

 of Heliconius of which H. erato (Fig. 18) is a good 

 example. The bright yellow patch on the forewing of 

 the Heliconius is very well imitated by the Pierine, and 

 on the hindwing of the latter the crimson patch of 

 E. tereas, etc, has been modified into a series of scarlet 

 stripes ; these being a palpable attempt to reproduce 

 the radiating chestnut streaks of H. erato or one of its 

 congeners. It is curious to see what slight modifications 

 between the two species of Euterpe enable them to 



