ting by loops in the papillae. The papillary
nerves run in a waving manner, usually terminating in loops.

Hair is an appendage of the skin and forms its external covering. It is a
special modification of epidermis, having the same essential structure, and
consists of a root, shaft, and point. The root has a bulbous extremity, is
lighter and softer than the stem, and is lodged in a recess or hair
follicle, which may either be in the corium or subcutaneous areolae. The
follicle is dilated at the bottom to correspond to the root bulb, and the
ducts of one or more sebaceous glands open into it. At the bottom of each
follicle is a conical, vascular papilla, similar in every respect to those
on the surface of the dermis; this papilla fits into a corresponding
depression in the root of the hair. The shaft consists of a center, or
medulla, a surrounding fibrous portion, and an external coating, or cortex.
The medulla consists of cells containing pigment or fat, is opaque, and
deeply colored. All kinds of hair do not have this medulla. The fibrous
portion occupies the bulk of the stem, and the cortex is merely a single
layer of thin, flat, imbricated (shinglelike) scales.

The sebaceous glands, lodged in the corium, are most abundant in parts
exposed to friction. They generally open into the hair follicles,
occasionally on the surface of the body. Each gland consists of a small
duct which terminates in a lobulated recess. These lobules vary, and are,
as is the duct, lined with epithelium. They are filled with sebaceous
matter which, as it is secreted, is detached into the sacs. They are very
plentiful between the claws of cattle.

The sudorific glands, or sweat glands, are situated in the subcutaneous
areolar tissue, surrounded by a quantity of fat. They are small, round,
reddish bodies, each of which consists of one or more fine tubes coiled
into a ball, the free end of the tube being continued up through the true
skin and cuticle, and opening on the surface. Each sweat gland is supplied
with a cluster of capillary blood vessels which vary in size, being very
large when perspiration is excessive. The contents of the smaller ones are
fluid, and of the larger, semifluid.

The skin may be regarded as an organ supplementary in its action to the
lungs and kidneys, since by its secretion it is capable of removing a
considerable quantity of water from the blood; it also removes small
quantities of carbon dioxid, salts, and in cer