CREATION BY EVOLUTION
of function in a given part. Notwithstanding this difficulty we know that many organs are truly vestigial, and such organs may be found in animals of almost any group.
Most insects are capable of flight and possess to this end a pair or, more commonly, two pairs of wings. Nevertheless many insects have wings that are entirely useless. Thus the male of the gipsy moth has well-developed wings and flies as other moths do; but the female, though she has fully formed wings, makes no use of them. When she emerges from her cocoon she creeps a short distance away and deposits
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A -
B
_p036_A_claws_in_a_python.png)
_p036_B_skeleton_supporting_claws_in_a_python.png)
Fig. 2.—A, Claws at the sides of the vent of a python, representing vestigial hind legs; B, Skeleton supporting the claws. After Romanes.
her eggs, but without flight. Her wings are functionless and in that sense vestigial. In many other insects the wings are not only useless but are relatively small. Examples are seen in certain chalcids, small, almost microscopic wasp-like creatures that are often parasitic in other insects. Wheeler has recently described an Australian ant, Monomorium subapterum (Fig. 1), in which the wings of the female are about half the size of normal wings and are quite without function. Such wings are clearly vestigial.
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