astigmatic in the left eye;
extremely myopic in the right. As the left eye gave such bad images
for near objects, he was compelled in childhood to mask it, and
acquired the habit of leaning his head on his left arm for writing,
so as to blind that eye, or of resting the left temple and eye on
the hand, with the elbow on the table. At the age of fifteen the
eyes were equalized by the use of suitable spectacles, and he soon
lost the habit completely and permanently. He is now the father of
two children, a boy and a girl, whose vision (tested repeatedly and
fully) is emmetropic in both eyes, so that they have not inherited
the congenital optical defect of their father. All the same, they
have both of them inherited his early acquired habit, and need
constant watchfulness to prevent their hiding the left eye when
writing, by resting the head on the left forearm or hand. Imitation
is here quite out of the question.

"Considering that every habit involves changes in the proportional
development of the muscular and osseous systems, and hence probably
of the nervous system also, the importance of inherited habits,
natural or acquired, cannot be overlooked in the general theory of
inheritance. I am fully aware that I shall be accused of flat
Lamarckism, but a nickname is not an argument."

To this Professor Ray Lankester rejoined (Nature, March 21, 1889):--

"It is not unusual for children to rest the head on the left forearm
or hand when writing, and I doubt whether much value can be attached
to the case described by Professor Hartog. The kind of observation
which his letter suggests is, however, likely to lead to results
either for or against the transmission of acquired characters. An
old friend of mine lost his right arm when a schoolboy, and has ever
since written with his left. He has a large family and
grandchildren, but I have not heard of any of them showing a
disposition to left-handedness."

From Nature (March 21, 1889) I take the second instance communicated
by Mr. J. Jenner-Weir, who wrote as follows:--

"Mr. Marcus M. Hartog's letter of March 6th, inserted in last week's
number (p. 462), is a very valuable contribution to the growing
evidence that acquired characters may be inherited. I have long
held the view that such is often the case, and I have myself
observed several instances of the, at least I may say, apparent
fact.

"Many years ago there was a very fine male of the Capra megaceros in
t