constitutes no objection. If it be granted that the possession of a 
common pattern is advantageous, there is no reason why its 
adoption should not be of frequent occurrence. 
2. Nor is the fact that the resemblances are largely independent 
of affinity adverse to the theories of BATES and MúLLER. Natural 
selection will work upon any material that comes to hand, quite 
irrespective of its taxonomic relations. 
3. That the female sex should be more liable to enter these 
associations is also to be expected. It is a matter of common 
observation that the female of many Birds and other Animals is 
better protected from attack by coloration and habits than the 
male; no doubt, as was pointed out by WALLACE, because the 
life of the female, as guardian of the future brood, is especially 
valuable to the species. Prof. POULTON has also drawn atten- 
tion to the fact that the female, being in Butterflies often 
more subject to individual variation than the male, gives greater 
scope to the operation of natural selection. 
4. The fact that the forms resembling each other are usually 
found together, finds a ready explanation; inasmuch as it implies 
that they have been exposed to the attacks of the same enemies. 
Otherwise, the adoption of a common aspect would carry no benefit. 
5. With regard to seasonal dimorphism, it is: generally found 
that the dry-season phases, which occur when Insect-life is scarce 
and competition among Insect-eaters is keen, are better protected 
than the wet-season phases of the corresponding species. Hence, 
we need not be surprised to find that in some cases the wet-season 
phase is mimetic, while the dry-season phase adopts for its pro- 
tection what is probably the more efficient method of cryptic 
coloration. Nor, again, is it surprising that a Butterfly like 
Belenois thysa, which is mimetic in both seasons, becomes much 
more strongly so in the dry. 
6. The fact that the changes from the normal are all in the 
direction of a resemblance that is merely superficial, is strongly in 
favour of the theories. For these superficial modifications are 
plainly an appeal to vision, and it is not easy to conjecture what 
alien vision can be of importance to these Insects, except the vision 
ot their actual or potential enemies. 
7. That the same apparent effect is often brought about by differ- 
ent means is quite characteristic of natural selection; which, as 
we have already seen, proceeds by adopting any means that 
offer, irrespective of affinity, homology, or any similar consider- 
ation. 
