148 ANTHROPOLOGY. 
difficult to ascertain; each appears to be an eminence or projection of the 
superficial lamin of the cutis, with some portion of the fibro-cellular tissue 
containing blood-vessels, and most probably nerves. The vessels appear 
as convoluted loops, and constitute the greater portion of the papille; 
nerves also can be traced through the cutis to each papilla. These accord- 
ingly may be considered as the true organs of tact. 
The excreting apparatus of the skin consists of glands and follicles, some 
of which supply the Paaee or sweat, others the sebaceous secretion 
or oily matter. 
The sudoriferous or sweat glands exist in all parts of the body, imbedded 
in the dermis or the subdermoid tissue. Hach. consists of a convoluted 
tube closed at its inferior extremity, the other end becoming the fine exha- 
Jant duct which passes in an oblique or spiral course through the cutis and 
cuticle, and opens by a minute pore; it is lined by a fine epithelium con- 
tinuous with the cuticle. 
The sebaceous glands, though not so numerous as the last, are very gene- 
rally diffused through all parts of the skin except the palit of the hands 
and soles of the feet. They are very distinct in the auditory meatus 
(giandes ceruminosce), on the inner aspect of the eyelids (glandes Merbo- 
miane), also on the scalp, face, and tip of the nose, around the nipples, and 
about the anus, scrotum, and corona glandis (glandes odorifere). ‘They 
..are small, round bodies, imbedded in the dermis; some are simple, soft, 
convoluted tubes, others are firm and lobulated. In the scalp and other 
parts where the hairs exist, one or more of them open into the hair follicles. 
A minute parasitic animal, the Demodex folliculorum, has been found to 
inhabit these ducts exclusively. The sebaceous secretion serves to keep 
the surface moist, soft, and pliant, and in particular situations, as in the ear, 
eyelids, nipples, &c., it answers special purposes; it also co-operates with the 
sudoriferous glands in separating hydro-carbonous matters from the blood. 
_ The hair and nails are appendages of the skin, but are rather modifica- 
tions of the cuticle than allied to the true skin. 
. 38. THE Natts cover the dorsal surface of the last phalanges of the fingers 
and toes, and have a tendency to extend around the extremity of each. 
They are strong, elastic, insensible plates, curved or concave so as to fit 
closely the cutis; the root and borders are concealed and fixed in a narrow 
deep fold in the cutis, termed the nail follicle ; the exposed portion or body 
ig convex and ends in the free margin. The surface of the cutis to which 
the body of the nail adheres is called the matrix, and is so vascular that the 
red color is seen through the nail; at the root and a short distance beyond 
it, it is less vascular and more dense, and causes the semi-lunar white spot 
at the base of the nail, called the Juwnula. The absence of this lunula is 
said to characterize the colored races, as distinguished from the white. In 
the follicle, at the root and borders, are a numlser of papillee which form 
the nail by secreting the blastema in which are formed cell germs; these 
become flattened and compressed, dry, and harden into nail. As the nail 
elongates, it thickens by additions to its concave surface from the matrix, 
and increases in breadth by secretion along its borders. The cuticle is 
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