[54] A very able anatomist of my acquaintance denies the inheritance of
mutilations and injuries, although he strongly believes in the
inheritance of the effects of use and disuse.
[55] _Variation of Animals and Plants under Domestication_, i. 467-469.
Lost toes were only seen by Dr. Dupuy in three young out of two hundred.
Obersteiner found that most of the offspring of his epileptic
guinea-pigs were injuriously affected, being weakly, small, paralysed in
one or more limbs, and so forth. Only two were epileptic, and both were
weakly and died early (Weismann's _Essays_, p. 311). A morbid condition
of the spinal cord might affect the hind limbs especially (as in
paraplegia) and might occasionally cause loss of toes in the embryo by
preventing development or by ulceration. Brown-Sequard does not say that
the defective feet were on the same side as in the parents (_Lancet_,
Jan., 1875, pp. 7, 8).
[56] _Variation of Animals and Plants under Domestication_, ii. 57.
[57] _Ibid._, ii. 392. Perhaps it might be better to suppose that the
_best_ gemmules were sacrificed in repairing the injured _nerve_, and
hence only inferior substitutes were left to take their place, and could
only imperfectly reproduce the injured part of the nervous system in
offspring.
[58] Hence perhaps Mr. Spencer's error in representing the epileptic
liability as permanent and as coming on _after_ healing (_Factors of
Organic Evolution_, p. 27).
[59] It is not claimed that the imperfect foot was on the same side of
the body as in the parent, and where parents had lost _all_ the toes of
a foot, or the whole foot, the few offspring affected usually had lost
only two toes out of the three, or only a part of one or two or three
toes. Sometimes the offspring had toes missing on _both_ hind feet,
although the parent was only affected in _one_. _One_ diseased ear and
eye in the parent was "generally" or "always" succeeded by _two_ equally
affected ears and eyes in the offspring (cf. _Pop. Science Monthly_, New
York, xi. 334). The important law of inheritance at corresponding
periods was also set aside. Gangrene or inflammation commenced in both
ears and both eyes soon after birth (pointing possibly to infection of
some kind); the epileptic period commenced "perhaps two months or more
after birth," while the loss of toes had occurred before birth. In no
case, as Weismann points out, is the original mutilation of the nervous
system ever transmitted. Even where an extirpated ganglion was never
regenerated in the parent, the offspring always regained the part in an
apparently perfect condition. On the whole the conflicting results ought
to be as puzzling to those who may attribute them to a universal
tendency to inherit the exact condition of parents as they are to those
who, like myself, are sceptical as to the existence of such a law or
tendency.
[60] The various results need to be fully and impartially recorded, and
they should also be well tested and confirmed in proportion as they
appear improbable and contrary to general experience. Professor Romanes
has been carrying out the necessary experiments for some time past.
[61] Natural History Museum, central hall, third recess on the left.
[62] _Traite de l'Heredite_, ii. 489; _Variation of Animals and Plants
under Domestication_, i. 469. If injuries are inherited, why has the
repeated rupture of the hymen produced no inherited effect?
[63] Compare the three cases of crooked fingers given in _Variation of
Animals and Plants under Domestication_, ii. 55, 240.
[64] _Ibid._, i. 460. Thus, where two brothers married two sisters all
the seven children were perfect albinos, although none of the parents or
their relatives were albinos. In another case the nine children of two
sound parents were all born blind (ii. 322).
[65] See pp. 179-182, _Evolution and Disease_, by J. Bland Sutton, to
whom and to our mutual friend Dr. D. Thurston I am indebted for
information on various points.
[66] _Variation of Animals and Plants under Domestication_, ii. 290; i.
454.