144 Dr. H. Eltringham on Specific and 



It is interesting to note that the flame pattern in these 

 Pierines is a copy of that occurring in the species of Heli- 

 conius belonging to Section II, and not those of Section I. 

 Pieris mandela locusta, Feld., $, and the form noctipennis 

 resemble to some extent H. saplio leuce, whilst Pereute 

 cJiarops, Boisd., $, resembles H. hydarus. On the underside 

 of the hind-wing (all that shows when at rest) the female 

 of Perrhybris lorena is very like H. antiochus aranea, though 

 the upperside is more like one of the Silvaniformes. A 

 similar silvaniform appearance is also presented by several 

 females of Perrhybris, though the resemblance is probably 

 secondary, both being influenced by Ithomiine models. 

 It seems unnecessary further to enumerate special cases 

 of mimicry connected with the genus. An examination 

 of any large collection will convince the observer of the 

 prevalence of mimetic patterns. 



Apart from a few exceptional instances, it appears to 

 be the rule that, whereas species of Heliconius belonging 

 to Section I are mimetic and constitute members of large 

 associations of which they are not themselves the dominant 

 models, species of Section II act as models and are imitated 

 either by forms of Section I or by butterflies of other 

 genera, and moths. The melpomene forms of Section I 

 seem to be all one species, whereas their counterparts in 

 Section II belong to several. Again, where a butterfly 

 of another genus appears to be a Heliconius mimic, its 

 model will almost always be found in Section II and not 

 in Section I. Thus Eueides finds its models in Section II. 

 Even Napeogenes duessa is apparently an incipient mimic 

 of an erato form which is very perfectly imitated by a 

 moth of the genus Pericopis. Moths of this genus come 

 into mimetic associations of which silvaniform Heliconii 

 are fellow members, but the moths are certainly not the 

 models, though Pericopis is doubtless a protected genus. 

 Distastefulness is a relative factor, and we are, of course, 

 quite justified in speaking of model and mimic, even in 

 Mullerian associations. The model is the form which, 

 from whatever cause, not necessarily palatability, has 

 attained to a greater predominance, and in the genus 

 Heliconius it would appear that, generally, the species of 

 Section II have in some way evolved a degree of such 

 predominance superior to that enjoyed by the species of 

 the other half df the genus. It is interesting to see an 

 independent property of this kind correlated with recognis- 



