patches on the underside of the hind-wing of many Pierines 
gives sufficient material for the assimilative process to work 
upon. 
The feebler development of the mimetic pattern in the 
males of this group calls for some explanation. No doubt 
the females stand in greater need of protection, but does 
there exist any active check on the fuller assumption of 
mimetic patterns by the males? The retention of the 
original white by the latter sex has been in similar instances 
attributed to female choice; Mr. Wallace on the other hand 
thinks it due to the difference of habits in the two sexes, the 
females alone flying in company with the mimicked Heliconi. 
But this leaves unexplained the presence of a partial mimetic 
pattern in the male. The probability is that although on 
the wing it may be advantageous rather than otherwise 
to the male, as Mr. Wallace thinks, to be taken for an 
ordinary white butterfly, yet when the insect is at rest, and 
settled with the wings erect, any Heliconine resemblance 
would be to some extent protective; and the whole aspect of 
these males, the underside alone of which shows any mimetic 
features, is the resultant of these two divergent tendencies. 
The mimetic features of the male cannot be regarded as a 
mere incidental result of the more complete transformation 
of the female, because in many species of other groups the 
female is completely mimetic while the male shows no ap- 
proach whatever to a mimetic change; moreover there is a 
species of Hesperochavis (H. hirvlanda) in which not only the 
male but both sexes show a partial mimetic pattern no 
further advanced than that of M. lorena 3 or M. pyrrha C. 
It is difficult to believe that in this case the pattern is not in 
some degree protective. 
Red basal spots like those of the mimicking Pierines are in 
some cases found in the mimicked Heliconit ; this is especially 
the case in those that form models for the Pierine genera 
Euterpe and Pereute. ‘These spots are too widespread in the 
Pierine subfamily to have arisen from imitation of the 
Heliconii; their presence in the latter is probably due to 
‘reciprocal mimicry” between distasteful forms, as sug- 
gested by the author in Trans. Ent. Soc. Lond., 1894, 
ps 298- 
