ldered cover of beetles,--men and
bulls, mammae: filaments without anthers in plants, mere scales
representing petals in others, in feather-hyacinth whole flower. Almost
infinitely numerous. No one can reflect on these without astonishment,
can anything be clearer than that wings are to fly and teeth <to bite>,
and yet we find these organs perfect in every detail in situations where
they cannot possibly be of their normal use{166}.

{165} Some of these examples occur in _Origin_, Ed. i. pp. 450-51,
vi. pp. 619-20.

{166} The two following sentences are written, one down the margin,
the other across the page. "Abortive organs eminently useful in
classification. Embryonic state of organs. Rudiments of organs."

The term abortive organ has been thus applied to above structure (as
_invariable_ as all other parts{167}) from their absolute similarity to
monstrous cases, where from _accident_, certain organs are not
developed; as infant without arms or fingers with mere stump
representing them: teeth represented by mere points of ossification:
headless children with mere button,--viscera represented by small
amorphous masses, &c.,--the tail by mere stump,--a solid horn by minute
hanging one{168}. There is a tendency in all these cases, when life is
preserved, for such structures to become hereditary. We see it in
tailless dogs and cats. In plants we see this strikingly,--in Thyme, in
_Linum flavum_,--stamen in _Geranium pyrenaicum_{169}. Nectaries abort
into petals in Columbine <_Aquilegia_>, produced from some accident and
then become hereditary, in some cases only when propagated by buds, in
other cases by seed. These cases have been produced suddenly by accident
in early growth, but it is part of law of growth that when any organ is
not used it tends to diminish (duck's wing{170}?) muscles of dog's ears,
<and of> rabbits, muscles wither, arteries grow up. When eye born
defective, optic nerve (Tuco Tuco) is atrophied. As every part whether
useful or not (diseases, double flowers) tends to be transmitted to
offspring, the origin of abortive organs whether produced at the birth
or slowly acquired is easily understood in domestic races of organisms:
[a struggle between the atrophy and hereditariness. Abortive organs in
domestic races.] There will always be a struggle between atrophy of an
organ rendered useless, and hereditariness{171}. Because we can
understand the origin of abortive organs in certai