The Making of Species 
on the ground amongst real dead leaves as a 
remarkable instance of protective form and 
colouration. And of course it may be that this 
is the correct explanation. But what enemy is 
this butterfly protected against? Upon hundreds 
of different occasions I have ridden and walked 
through forests where Precis artexia was 
numerous, and I have caught and preserved 
many specimens of these butterflies, but never 
once did I see a bird attempting to catch one 
of them. Indeed, birds of all kinds were scarce 
in the forests where these insects were to be 
found.” 
Similarly D. Dewar writes (Albany Review, 
1907): ‘If a naturalist be asked to cite a perfect 
example of protective colouring, he will, as likely as 
not, name the sand grouse (Pteroclurus exustus). 
This species dwells in open, dry, sandy country, 
and its dull brownish-buff plumage, with its soft 
dark bars, assimilates so closely to the sandy 
environment as to make the bird, when at rest, 
practically invisible, at any rate to the human 
eye. Unfortunately for the theory, this bird 
stands less in need of protective colouration than 
any other, for it has wonderful powers of flight. 
Even a trained falcon is unable to catch it, 
because it can fly upwards in a straight line as 
though it were ascending an inclined plane, with 
the result that the pursuing hawk is never able 
to get above it to strike.” 
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