NOSE. 
: the mucous membrane lining all the supple- 
mental cavities, the nasal duct and lacrymal 
sac, and the upper part of the pharynx. 
The course (as it is called) of the mucous 
membrane next merits consideration. Ascend- 
ing from the floor of the nasal fossa up the 
outer side of the inferior meatus, it becomes 
gradually thicker and more spongy. From this 
meatus it is continued anteriorly into the nasal 
duct, around whose lower orifice it forms an 
annular fold or reduplication. The orifice in 
the bones is elliptical and rather obliquely 
placed, its anterior edge being somewhat lower 
than the posterior. The fold of mucous mem- 
brane around it is especially deep on the inner 
side and posteriorly, and not only contracts 
the size of the orifice, but acts as a valve to 
_ guard it, and, when pressed upwards and for- 
_ wards, to close it. Hence, though some per- 
sons can inflate their lachrymal sacs, in most 
men, when the nostrils are closed, and air is 
_ pressed forcibly into the nose from behind, 
__ hone ever escapes from its cavities. 
___ As the lining membrane descends again upon 
_ the outer surface of the inferior turbinated bone, 
it becomes thicker, more spongy, and more vas- 
_ cular. At the lower edge of the bone it forms 
a deep fold, which, in its congested state, 
touches the floor of the cavity. The fold is 
peculiarly thick at the two ends of the bone, and 
in disease in scrofulous children it sometimes 
_ forms a loose and very vascular spongy mass, 
which has been mistaken, it is said, for a poly- 
F 4G Immediately behind the deep posterior 
fold the membrane becomes again thin and ad- 
heres closely to the pterygoid plate of the 
‘Sphenoid bone, behind which, and on a level 
with the extremity of the inferior turbinated 
 boné, it is continued into the orifice of the 
_ Eustachian tube. 
As it passes from the inferior turbinated bone 
_ to the outer wall of the middle meatus, the 
_ Schneiderian membrane becomes again thinner 
and more compact. About the middle of this 
‘meatus it enters the deep channel of the infun- 
_ dibulum, whose form it scarcely alters, and 
_ along which it passes to the anterior ethmoidal 
 ¢ells, and through them to the frontal sinuses.- 
_ Above the commencement of the infundibulum 
_ it enters into the antrum by a narrow orifice 
directed obliquely from before backwards. Of 
"the great opening into the antrum when the 
Superior maxillary bone is separated, a large 
Portion is covered by the palatine and turbi- 
nated bones ; and of what remains, all but a 
Narrow circular orifice at the upper and anterior 
‘part is closed by a thick annular fold of the 
mucous membrane; and even permanent closure 
is no rare consequence of the swelling to which 
the membrane is subject. Cloquet* says that 
this fold contains in man a gland with numer- 
ous orifices analogous to one of large size which 
Surrounds the orifice of the antrum in many 
animals. I have not been able to find such a 
structure, and even E. H. Weber+ has not been 
more successful, 
* Osphresiologie, p. 247. 
+ Hildebrandt’s Anatomie, Bd. iv. 
731 
The membrane covering the middle turbi- 
nated bone and the anterior portion of the cel- 
lular part of the ethmoid is thick and spongy, 
but less so than that on the inferior turbinated 
bone. In the superior meatus it is thin; and 
it becomes still thinner as it passes into the 
one or more orifices of the posterior ethmoidal 
cells, on the borders of which it is tightly ap- 
plied, and whose size, as it forms no loose pro- 
jecting fold, it diminishes but little. It closes, 
at this part, the spheno-palatine foramen} and 
in the vault of the nasal fosse all the foramina 
of the cribriform plate, through which nerves 
and vessels are admitted to the outer surface of 
the mucous membrane, and the inner surface 
‘of the periosteum. At the lower borders of the 
superior and middle turbinated bones it forms 
thick folds, which make the meatus appear far 
smaller than they do in the dry bones. These 
folds are not so deep as that on the inferior tur- 
binated bone; but, as they probably receive 
many filaments of the olfactory nerve, both they, 
and perhaps the inferior fold also, may be 
regarded as means for the multiplication of the 
sensitive surface, and as analogous, in some 
measure, to the folds of mucous membrane by 
which alone in Fish and the Proteus anguinus 
the same object is attained 
In all the rest of its extent over the septum, 
the nasal bones, and the lateral cartilages, the 
Schneiderian membrane has a uniform surface 
and is of about middle thickness: its layers 
are intimately united, and it adheres with mode- 
rate firmness to the bone and cartilage. 
Nerves of the nose.-—The olfactory nerve, 
or, as it may be more properly called, the 
olfactory lobe of the brain, arises from the 
posterior, inner, and inferior part of the an- 
terior lobe of the cerebrum. It lies in the 
groove between the two most internal of the 
convolutions of this part of the brain, and may 
be divided into three parts ;—the posterior, 
or pyramid, the anterior, or bulb, and the 
middle, or proper ¢runk of the nerve or lobe. 
At its origin it may be traced backwards into 
three roots. Of these, the outer or long root 
appears first in the fissura Sylvii at the junction 
of the anterior and middle lobes of the cerebrum, 
just above the trunk of the middle cerebral 
artery. Hence, its chief portion proceeds in- 
wards, forwards, and a little downwards on the 
under surface of the anterior lobe and in front 
of the substantia perforata antica; and on 
coming near the other roots it turns more 
directly forwards and unites with them at the 
beginning of the groove between the two convo- 
lutions. In this course it receives on its outer 
border.one or more separate fasciculi, which 
come from the deeper part of the lobe and are 
sometimes completely concealed by grey mat- 
ter covering them. 
The inner or short root is first visible at the 
inner and posterior part of the anterior lobe of 
the cerebrum, in front of the beginning of the 
fissura Sylvii, and just outside the great me- 
dian division of the cerebrum. It consists of 
one or more fasciculi, and passes outwards and 
forwards to the commencement of the groove, 
where, curving round like the preceding, but 
