Mimetic Attraction. 325 
nothing but the mimic; while in the latter case (Miillerian 
mimicry) the mimetic attraction is unlimited and mutual, 
acting reciprocally in both directions and influencing each 
member of the group. 
This doctrine of the mutual attraction between inedible 
forms, leading not merely to the copying of one by 
another, but to the departure of each from its original 
aspect by the adoption of features belonging to the other, 
is not simply a speculation, nor does it rest only on 
a priori reasoning. ‘There is much evidence that 
it represents a fact which does actually take place in 
nature ; and in the two papers above referred to* I have 
brought forward cases which seem inexplicable by any 
other principle. I may be allowed to add in this place a 
further instance, which appears to me for several reasons 
remarkable. 
The instance of P. locusta $. In Trans. Ent. Soc. 
Lond. 1896, p. 72, note, I spoke, though somewhat 
doubtfully, of P. locusta f as a mimic. My suspicion 
that this was the case at that time fell short of actual 
conviction. Now, however, after a further careful 
examination of P. locusta ~ from this particular point 
of view, I have little or no hesitation in pronouncing it to 
be a member of a mimetic association of an exceptionally 
interesting kind. 
It will be remembered that the males of Mylothris 
lorena, M. pyrrha, ete., form a good illustration of the 
accurate manner in which the appropriate habits are 
correlated with adaptive colouring—the mimetic pattern 
in these instances being confined to the underside, and 
being in all probability useless as a protection except 
during the resting position; while the habits of these males, 
as testified to by Wallace,t are such as would probably 
render a Heliconiine resemblance during flight a source of 
danger to its possessors rather than of safety. Similarly 
in P. locusta Z, it is only on the underside that the 
mimetic pattern appears, and here again there can be 
* See also an abstract in“ British Association Reports,” 1894, 
p. 692. 
t+ “ Tropical Nature,” 1878, p. 205. See also Haase, op. cit., 
p. 68. It should, however, be stated that neither of these authors 
assigns any protective value to the underside of the male forms in 
question. 
