of prominences, commonly known as "goose-pimples."

[Illustration: Fig. 47.
A section of the skin, showing its arteries and
veins. A, A. Arterial branches. B, B. Capillaries
in which the branches terminate. C. The venous
trunk into which the blood from the capillaries
flows.]

The internal, or fibrous layer of the skin, contains numerous
depressions, each of which furnishes a receptacle for fat. While the
skin is supplied with a complete net-work of arteries, veins, and
nerves, which make it sensitive to the slightest touch, it also contains
numerous lymphatic vessels, so minute that they are invisible to the
naked eye.

Among the agents adapted for expelling the excretions from the system,
few surpass the _Sudoriferous Glands_. These are minute organs which
wind in and out over the whole extent of the true skin, and secrete the
perspiration. Though much of it passes off as insensible transpiration,
yet it often accumulates in drops of sweat, during long-continued
exercise or exposure to a high temperature. The office of the
perspiration is two-fold. It removes noxious matter from the system, and
diminishes animal heat, and thereby equalizes the temperature of the
body. It also renders the skin soft and pliable, thus better adapting it
to the movements of the muscles. The _Sebaceous Glands_, which are
placed in the true skin, are less abundant where the sudoriferous glands
are most numerous, and _vice versa_. Here, as elsewhere, nature acts
with systematic and intelligent design. The perspiratory glands are
distributed where they are most needed,--in the eyelids, serving as