ss of evidence collected by Mr. Darwin and a host of other writers, to
the effect that mutilations are sometimes inherited, than does Mr.
Wallace, who says that, "as regards mutilations, it is generally admitted
that they are not inherited, and there is ample evidence on this point."
It is indeed generally admitted that mutilations, when not followed by
disease, are very rarely, if ever, inherited; and Mr. Wallace's appeal to
the "ample evidence" which he alleges to exist on this head, is much as
though he should say that there is ample evidence to show that the days
are longer in summer than in winter. "Nevertheless," he continues, "a
few cases of apparent inheritance of mutilations have been recorded, and
these, if trustworthy, are difficulties in the way of the theory." . . .
"The often-quoted case of a disease induced by mutilation being inherited
(Brown-Sequard's epileptic guinea-pigs) has been discussed by Professor
Weismann and shown to be not conclusive. The mutilation itself--a
section of certain nerves--was never inherited, but the resulting
epilepsy, or a general state of weakness, deformity, or sores, was
sometimes inherited. It is, however, possible that the mere injury
introduced and encouraged the growth of certain microbes, which,
spreading through the organism, sometimes reached the germ-cells, and
thus transmitted a diseased condition to the offspring." {35}

I suppose a microbe which made guinea-pigs eat their toes off was
communicated to the germ-cells of an unfortunate guinea-pig which had
been already microbed by it, and made the offspring bite its toes off
too. The microbe has a good deal to answer for.

On the case of the deterioration of horses in the Falkland Islands after
a few generations, Professor Weismann says:--

"In such a case we have only to assume that the climate which is
unfavourable, and the nutriment which is insufficient for horses, affect
not only the animal as a whole but also its germ-cells. This would
result in the diminution in size of the germ-cells, the effects upon the
offspring being still further intensified by the insufficient nourishment
supplied during growth. But such results would not depend upon the
transmission by the germ-cells of certain peculiarities due to the
unfavourable climate, which only appear in the full-grown horse."

But Professor Weismann does not like such cases, and admits that he
cannot explain the facts in connection with the climatic va