1186 THE STRUCTURE OF EVOLUTIONARY THEORY
speculation leading to false assumptions about the need for such functionalist
mechanisms as natural selection (pp. 2-3):
He [the morphologist] has the help of many fascinating theories within the
bounds of his own science, which, though a little lacking in precision, serve
the purpose of ordering his thoughts and of suggesting new objects of enquiry.
His art of classification becomes a ceaseless and an endless search after the
blood relationships of things living, and the pedigrees of things dead and
gone. The facts of embryology become ... a record not only of the life-history
of the individual but of the annals of its race... Every nesting bird, every
anthill or spider's web displays its psychological problems of instinct or
intelligence. Above all, in things both great and small, the naturalist is
rightfully impressed, and finally engrossed, by the peculiar beauty, which is
manifested in apparent fitness or "adaptation,"—the flower for the bee, the
berry for the bird.For all its Victorian amplitude, D'Arcy Thompson usually imposes adequate
restraint upon his literary talents. But he does occasionally soar "over the top," and
nothing incites this tendency more than his aversion to Darwinian speculation in the
adaptationist mode—as in the following example (pp. 671-672):
Some dangerous and malignant animals are said (in sober earnest) to wear a
perpetual war paint. The wasp and the hornet, in gallant black and gold, are
terrible as an army with banners; and the Gila Monster (the poison-lizard of
the Arizona desert) is splashed with scarlet—its dread and black complexion
stained with heraldry more dismal. But the wasp-like livery of the noisy, idle
hover-flies and drone-flies is but stage armour, and in their tinsel suits the
little counterfeit cowardly knaves mimic the fighting crew.
The jewelled splendour of the peacock and the humming-bird, and the less
effulgent glory of the lyrebird and the Argus pheasant, is ascribed to the
unquestioned prevalence of vanity in the one sex and wantonness in the other.
The zebra is striped that it may graze unnoticed on the plain, the tiger that it
may lurk undiscovered in the jungle; the banded Chaetodont and Pomacentrid
fishes are further bedizened to the hues of the coral reefs in which they dwell.
The tawny lion is yellow as the desert sand; but the leopard wears its dappled
hide to blend, as it crouches on the branch, with the sun-flecks peeping
through the leaves...
To buttress the action of natural selection the same instances of
"adaptation" (and many more) are used, which in an earlier but not distant age
testified to the wisdom of the creator and revealed to simple piety the high
purpose of God.At this turning point in his argument, D'Arcy Thompson calls upon his expertise
in classics to invoke Aristotle's exegesis of causality in his favor. We may
acknowledge that biological forms embody "purposes" expressed as