Part 77

EXAMINATION OF THE PILOUS SYSTEM IN THE DIFFERENT REGIONS.

I. Pilous System of the Head.

General observations. 379

Of the Hair.—Its length, situation, limits, influence on physiognomy, variety according to sex, uses, thickness, fundamental colours, shades, and influence on temperament. 381

Eyebrows.—Their general arrangement.—Their motions. 386

Eyelashes.—Their form, arrangement, &c. 387

Beard.—It is the attribute of the male.—Its relations with strength.—Of our habits in relation to the beard. 388

II. Of the Pilous System of the Trunk.

Its varieties according to the regions. 390

III. Pilous System of the Extremities.

Its varieties.—It is wanting on the palms of the hands and the soles of the feet. ib.

ARTICLE SECOND.

ORGANIZATION OF THE PILOUS SYSTEM.

I. Origin of the Hairs.

Of the membranous canal which encloses this origin.—Relation of the hair with this canal.—Organization of this.—Swelling of the hair and its origin.—Its course to the exterior. 391

II. External Covering of the Hairs.

Analogy of this covering with the epidermis.—Its differences.—Action of the different agents upon this covering.—Its external arrangement. 394

III. Internal Substance of the Hairs.

We are ignorant of its nature.—Capillaries of the hairs of the head.—Their colouring substance.—The internal substance of the hairs of the head is essentially subjected to the influence of the vital phenomena.—Proof of this assertion.—This distinguishes it from the external covering. 396

ARTICLE THIRD.

PROPERTIES OF THE PILOUS SYSTEM.

It undergoes but little horny hardening.—Of curling.—The properties of texture slightly marked.—The animal ones are nothing.—The organic are a little more evident. 401

ARTICLE FOURTH.

DEVELOPMENT OF THE PILOUS SYSTEM.

I. State of this System in the First Age.

Of the down of the fœtus.—The growth of the hairs is then the reverse of that of the other parts.—Their growth after birth.—Their colours are a little deeper in infancy. 403

II. State of the Pilous System in the following Ages.

Revolution at puberty.—Of the hairs which then appear.—There are but few changes in the following ages. 404