Papilio dardanus (merope) and Acrxa johnston, 311 
colour there probably arose still more perfect mimics of 
the same models in proteina and flavescens, the two forms 
of johnstont which are nearest to fallav. It is to be 
observed that the change in the shape of the fore-wing 
which occurred as fallax gave rise to johnstont is in the 
direction of the form of the Danaine and Planema models. 
Johnstoni once formed, variation in other directions, guided 
by natural selection, led to the mimicry of various 
additional Danaine and Acreine models: — of Limnas 
chrysippus, var. dorippus, of Planema quadricolor, Planema 
latifasciata, and Planema pogger. 
[My friend Mr. Guy A. K. Marshall has kindly read 
through the proof-sheets of this paper, and has made 
many valuable suggestions. | 
