150 ANTHROPOLOGY. 
substance called fat. In the cellular or areolar tissue, on the other hand, we 
have numerous bands or threads of white fibrous tissue crossing each other, 
and leaving interstices which communicate freely. The two: tissues are 
usually associated together, the adipose being inclosed in the meshes of the 
areolar, but in some situations, as in the medullary canal of the long bones 
(where it is known as the marrow), in the omenta, along the mesenteric 
vessels, and upon the heart, the adipose tissue may be abundant, with little 
or no cellular. dsne¢ 
_ Adipose tissue consists of two distinct elements, the secreting membrane 
and the secreted product. The former consists of fine transparent mem- 
branous cells surrounded by capillaries; each sac is somewhat round, but 
by aggregation and consequent compression is made to assume various 
figures. The vessels pass in the interstices between the cells, and surround 
each by a delicate inosculation. The adeps or fat, which occupies each 
cell, is a soft, yellowish, oily substance, presenting a great variety with the 
individual. In youth it is most abundant towards the exterior, the réverse 
existing in old age. The fat contributes to the covering of the body, and 
being a bad conductor of heat, assists in retaining its temperature; by fill- 
ing up numerous interstices, it adds to the compactness and symmetry of 
the system; it may also serve as a reservoir of nutritive materials from 
which the system may derive an occasional supply. 
Pl. 129, fig. 24, vertical section of the skin showing its microscopical 
structure: *, epidermis with its undulating lines; *, sudoriferous gland and 
eanal; *, cutis vera; *, apparatus for secreting pigment substance; °, seba- 
ceous gland with its duct; °°, papille; ’, blood-vessels of the skin. fg. 
25, vertical section of the thumb to exhibit the insertion of the nail: *, nail; 
*? continuation of the cuticle; *, cutis vera; ° (left hand side), adipose tis- 
sue; *, fold of skin containing the root of the nail; °, section of the terminal 
bone of the thumb. Fg. 26, body of the thumb nail: ’, lateral fold; 
*, ridges caused by the linear rows of papillz on the subjacent cutis vera ; 
*, lunula or spot at the base of the nail. 
2. ANATOMY OF THE NOSE, OR ORGAN OF SMELL. 
The nose is situated between the orbits, above the mouth and glottis, 
and in front of the pharynx and of each tympanum, communicating with 
all these regions. Though median in position it is really a double organ, 
being completely divided by a partition or septum into two symmetrical 
portions, called the nares or nasal fossee. The nasal passages have a two- 
fold use: they constitute the organ of smell, the olfactory nerve being dis- 
tributed to the vascular membrane covering their irregular and convoluted 
aspect; and secondly, they serve as avenues to the respiratory organs. 
We may conveniently examine the nose as composed of two portions: the 
one, anterior or external (the nose proper), consisting of cartilages and soft 
parts; the other, posterior or internal, the nares or nasal fossz, composed 
of bones covered by highly vascular mucous membrane. 
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