(ali) 
group with a broad the other to the group with a narrow 
band of glistening scales, in the male,—bands which are pre- 
sumably scent-producing. It is probable that the excessively 
close resemblance between these pairs and between the 
members of the Eupleine associations has been rendered 
possible without injury to the species by the existence of this 
means of instant recognition, and I think it is possible to infer 
the past history with a fair degree of probability. In the 
African Danaine genus Amawris we find two very common 
species as closely alike as any of the Euplceine or Heliconine 
Miillerian groups or pairs. I refer to Amauris echeria and A. 
albimaculata. It was at first thought that white spots in 
place of buff in the fore-wing alone distinguished these forms, 
and the general opinion followed that one was a variety of the 
other. But Rothschild and Jordan have shown that they are 
certainly separated by minute but well-defined and constant 
differences. Accompanying these, the scent-patches at the 
anal angle of the hind-wing of the male of albimaculata are 
about twice as long as those of echeria. It is probable that 
this wide difference has been a powerful aid in rendering 
possible the extraordinarily close resemblance. Already both 
species of this pair have undergone subspecific changes in 
different parts of their geographical range, the southern forms 
being replaced respectively by echeria jacksoni and albimaculata 
hanningtont in the equatorial parts of the eastern side of 
Africa. In the Oriental Region the even more dominant 
Eupleine group originated far more complex communities, 
probably in consequence of the development of further 
modifications of the male brands of one or both members 
of an ancestral pair, until synaposematic associations contain- 
ing 3, 4 or more species arose, widened their range and spread 
into islands. Thus each of the component species became at 
first different sub-species and finally distinct species in various 
parts of the total area of distribution. The synaposematic 
Heliconine pairs,on the other hand, may in large part have 
reached their present condition by continuing the history 
begun by the two African species of Amauwris. I say “in 
large part” because when Mr. Kaye very kindly arranged 
the Oxford Heliconine a few weeks ago we saw evidence for 
