Protective Coloration in its relation to Mimicry, etc. 557 
more easily recognize minute patterns than colour, when 
we realize that the perfect colour-adaptation of innumerable 
forms of life, from mammals to larve, proves that the lower 
animals see colour (since otherwise such adaptation would 
not be necessary for their concealment). In each form of 
protective coloration there exist cases so pronounced as 
to leave no doubt of their use. Each of these has been 
assumed to be mimicked, or, at least, echoed, for some 
reason, by other species than the one in which it is most 
perfect. Let us look at the dead-leaf pattern, z.¢. the 
pattern that represents, in the most minute degree, 
substance of the colour and thickness of dead leaves, and 
lying as near the ground as dead leaves usually lie. This 
pattern is marvellously perfect on the Copperhead snake 
(Trigonocephalus contortriz), on some Boas, on that form 
of domestic cat which has the most tiger-cat-like black 
and grey pattern (as well as, in fact, on tiger-cats them- 
selves), and on several Sphinx moths. Of course, when 
this leaf-representation occurs on the rotundity of animals’ 
bodies, as in the cats or snakes, it exists only in 
co-operation with the regular effacive gradation, but on 
the flat plane of a Sphinx’s upper-wing-surface it has 
and needs no such co-operation. In the Sphinx-moth 
photograph which I have sent Professor Poulton, this 
reproduction of thin material casting a shadow on the 
surface it lies on is past all mistaking. This artifice is 
present on many moths, and its elements are traceable in 
such butterfly genera as Vanessa, Grapta, and many 
others. To know at what point in the long series of 
somewhat similarly marked species the original function 
has ceased, would require impossible study. 
While it is plain that a hundred needs may each be 
represented in the pattern- and colour-schemes of animals, 
it is also plain to an artist’s eye that in most butterflies all 
visible details of colour, pattern, and form are essential 
parts of the representation of flower-scenery. And it is 
surely conceivable that, in a certain region, one particular 
form of flower-scenery-representation may furnish such 
advantages to butterflies as to cause many widely-separated 
species to become modified till they wear a common aspect; 
and it is conceivable also that there would be one common 
form of wing which would best lend itself to this scheme. 
Surely we do not know enough of the habits of these 
insects or of the regions that may be their strongholds to 
