that this has never been proved either by means of
direct observation or by experiment. "It must be admitted," he
writes, "that there are in existence numerous descriptions of cases
which tend to prove that such mutilations as the loss of fingers,
the scars of wounds, etc., are inherited by the offspring, but in
these descriptions the previous history is invariably obscure, and
hence the evidence loses all scientific value."

The experiments of M. Brown-Sequard throw so much light upon the
question at issue that I will quote at some length from the summary
given by Mr. Darwin in his Variation of Animals and Plants under
Domestication. {279} Mr. Darwin writes:--

"With respect to the inheritance of structures mutilated by injuries
or altered by disease, it was until lately difficult to come to any
definite conclusion." [Then follow several cases in which
mutilations practised for many generations are not found to be
transmitted.] "Notwithstanding," continues Mr. Darwin, "the above
several negative cases, we now possess conclusive evidence that the
effects of operations are sometimes inherited. Dr. Brown-Sequard
gives the following summary of his observations on guinea-pigs, and
this summary is so important that I will quote the whole:--

"'1st. Appearance of epilepsy in animals born of parents having
been rendered epileptic by an injury to the spinal cord.

"'2nd. Appearance of epilepsy also in animals born of parents
having been rendered epileptic by the section of the sciatic nerve.

"'3rd. A change in the shape of the ear in animals born of parents
in which such a change was the effect of a division of the cervical
sympathetic nerve.

"'4th. Partial closure of the eyelids in animals born of parents in
which that state of the eyelids had been caused either by the
section of the cervical sympathetic nerve or the removal of the
superior cervical ganglion.

"'5th. Exophthalmia in animals born of parents in which an injury
to the restiform body had produced that protrusion of the eyeball.
This interesting fact I have witnessed a good many times, and I have
seen the transmission of the morbid state of the eye continue
through four generations. In these animals modified by heredity,
the two eyes generally protruded, although in the parents usually
only one showed exophthalmia, the lesion having been made in most
cases only on one of the corpora restiformia.

"'6th. Haematoma and dry gangrene of the ear