ORGANS OF SENSE. 15) 
TE Noss is essentially formed of cartilages; one occupies the median 
line or septum, the others are placed on each side and form the ale. ‘They 
are continuous laterally with the superior maxillary, and superiorly with 
the margin of the nasal bones; inferiorly they bound two oval openings, 
the nostrils. Each nostril has its long axis, antero-posterior, and is partly 
surrounded by stiff hairs (vibrille), which bend across it and instantaneously 
give notice of the entrance of foreign particles. The skin covering the tip 
of the nose is thickened, and furnished with numerous sebaceous follicles, 
the mouths of which frequently appear like black dots, owing to the adhe- 
sion of extraneous particles. The secretion of these follicles may often be 
foreed out in fine long threads like small worms. 
The cartilages of the nose or fibro-cartilages are five in number, one in 
the centre, one at each side, and one inferiorly in each ala. The septal or 
median cartilage is a true cartilage of considerable strength; it not only 
separates the nostrils, but also the anterior portions of the nasal fosse. It 
is inclosed in thick mucous membrane, and is not always vertical, but may 
project to one side. 
The lateral nasal cartilages are two on each side, superior and inferior. 
The superior lateral is attached externally and posteriorly to the nasal pro- 
cess of the superior maxillary bone and to the inferior margin of the nasal; 
anteriorly and internally to the opposite one and to the septal cartilage, and 
inferiorly by fibrous tissue to the inferior cartilages. The injerior lateral or 
alar cartilages form the upper part of each ala, the tip or lobe and the 
boundary of the nasal openings. All the lateral cartilages are readily acted 
on by the superimposed muscles, which can move the whole organ, or alter 
the shape of the openings, but cannot perfectly close them. 
Pi. 182, fig. 29, left side of the nose of an adult, the cuticle supposed to 
be removed for the purpose of more clearly exhibiting the openings of the 
sebaceous follicles. ig. 80, lateral view of the bones and cartilages of the 
nose: a, a, skin of the nose; 6, left nasal bone; c, left superior lateral car- 
tilage; d, left alar cartilage with its three appendages, e, f, g, which are 
attached to each other by the ligaments h, 7, &. ig. 31, anterior view of 
the nasal cartilages: a, b, nasal bones; ¢, d, superior lateral cartilages; e, 
septum; 7, f, small cartilages proceeding from it; g-o, alar cartilages with 
their three appendages. Jig. 32, outline view of the preceding figure. 
Fig. 38, ferior view of the nasal cartilages: a, b, c, d, outline of the nose; 
é, septal or median cartilage; /, extremity of the upper jaw to which it is 
attached; g—k, alar cartilage of the left side with its three appendages; Lo, 
do. of the right side. /%g. 34, superior lateral cartilage of the nose. Fig. 
35, septal cartilage of the nose. Mig. 36, left alar cartilage. ig. 37, do. 
with its three appendages (from without). Fg. 38, do. from within. Js. 
89 and 40, the three small cartilaginous appendages, without and within. 
THE Nasa Fossa are bounded by several bones which are covered by 
a very delicate periosteum; to the anterior part of the bones of the nose 
are attached the cartilages already described. These several bones are the 
nasal, frontal, ethmoid, sphenoid, superior maxillary, palatine, unguis, 
spongy, pterygoid, and vomerine bones. The external wall of each naris is 
x 857 
