(24

[Note in another hand:] pp. 162/3

(24

Ch. VI.

is an action full of meaning meaning & of real service real service.

We have already seen that the contraction of the orbicular muscles leads to the drawing up of the upper lip, & to the productions of the naso-labial furrow on of the cheeks consequently, if as the mouth is mouth must be widely opened, to the contraction of the p depressor muscles of the corner of the mouth.

The production formation of the naso-labial furrow naso-labial fold on the cheeks, likewise follows from the drawing up of the upper lip. Thus all the chief expressive movements of the face during crying seem to follow from the contraction of the muscles round the eyes. We shall immediately see that the shedding of tears apparently depends, like the contraction of the muscles round the eyes, on the eyeballs likewise stands in some close relation tending to become gorged with blood during the act of screaming.

with the contraction of these same muscles.)

[24v]

[Note in another hand:] Desct of Man [p. 116]

With our domestic

for believing that cold & damp directly affect the growth of the hair; but I have not met with any evidence on this head with man.

Effects of the increased Use & Disuse of Parts.—

It is well known that use in the individual strengthens the muscles, & complete disuse, or the destruction of the proper nerve, causes them to atrophy. So when the eye is destroyed the optic nerve often becomes atrophied. When an artery is tied, the lateral channels increase not only in diameter, but in the thickness &