110 MIMICRY, AND OTHER PROTECTIVE 
influence all groups related to each other in an equal 
degree. Again, the general fact that those species 
which mimic others are rare, while those which are 
imitated are abundant, is in no way explained by either 
of these theories, any more than is the frequent occur- 
rence of some palpable mode of protection in the 
imitated species. “Reversion to an ancestral type” 
no way explains why the imitator and the imitated 
always inhabit the very same district, whereas allied 
forms of every degree of nearness and remoteness 
generally inhabit different countries, and often dif- 
ferent quarters of the globe; and neither it, nor 
“ similar conditions,’’ will account for the likeness be- 
tween species of distinct groups being superficial only— 
a disguise, not a true resemblance; for the imitation 
of bark, of leaves, of sticks, of dung; for the resem- 
blance between species in different orders, and even 
different classes and sub-kingdoms; and finally, for the 
graduated series of the phenomena, beginning with a 
general harmony and adaptation of tint in autumn and 
winter moths and in arctic and desert animals, and 
ending with those complete cases of detailed mimicry 
which not only deceive predacious animals, but puzzle 
the most experienced insect collectors and the most 
learned entomologists. 
Mimicry by Female Insects only. 
But there is yet another series of phenomena con- 
nected with this subject, which considerably strengthens 
the view here adopted, while it seems quite incompa- 
