and this may seem an extremely simple operation, but he who has taught
a child to put on gloves, knows that this is by no means the case.


[4] See for my authorities, and for various analogous facts,
`The Variation of Animals and Plants under Domestication,'
1868, vol. ii. p. 304.

[5] `The Senses and the Intellect,' 2nd edit. 1864, p. 332. Prof. Huxley
remarks (`Elementary Lessons in Physiology,' 5th edit. 1872, p.
306), "It may be laid down as a rule, that, if any two mental states be
called up together, or in succession, with due frequency and vividness,
the subsequent production of the one of them will suffice to call up
the other, and that whether we desire it or not."

When our minds are much affected, so are the movements of our bodies;
but here another principle besides habit, namely the undirected overflow
of nerve-force, partially comes into play. Norfolk, in speaking
of Cardinal Wolsey, says--

"Some strange commotion
Is in his brain; he bites his lip and starts;
Stops on a sudden, looks upon the ground,
Then, lays his finger on his temple: straight,
Springs out into fast gait; then, stops again,
Strikes his breast hard; and anon, he casts
His eye against the moon: in most strange postures
We have seen him set himself."--_Hen. VIII_., act 3, sc. 2.