102 DR, E, KLEIN. 
b. A very delicate basement membrane separates the epithe- 
lium from the next or the subepithelial fibrous layer. This 
layer is chiefly composed of bundles of fibrous tissue, and in it 
are capillary vessels, and here and there 4 thin bundle of un-_ 
striped muscle cells. ‘The thickness of this layer varies in dif- 
ferent places ; in about the middle of the lateral wall it is about 
0°032 mm. 
c. The next outer layer is the layer of the cavernous tissue ; 
/ this layer is thickest in about the middle of the lateral wall ; it 
is altogether wanted near the upper and lower suleus. The 
thickest diameter is about 0°12 mm. But at the places in 
which the cartilage capsule is incomplete, the thickness of this 
layer is much greater, being 0°22 mm. The length of this 
layer varies between 0°43 and 0°61 mm. 
The matrix of this layer is fibrous tissue, containing a plexus 
of bundles of unstriped muscle cells. The essential parts are 
large venous vessels connected into a plexus, the vessels running 
chiefly parallel to the long axis of the organ, hence in a transverse 
section most of them appear cut transversely. The transverse 
diameter of the vessels varies between 0°046 and 0°092 mm. 
Where the cartilage capsule is wanting, some of the vessels are as 
large as 0°16 mm. in diameter. These vessels take up the 
venous capillaries of the subepithelial fibrous layer as well as 
some of those of the next outer glandular layer. The efferent 
veins of the cavernous layer are smaller than the vessels of this 
layer, a character essential of a cavernous tissue. 
d. The layer of glands (Jacobson’s membrane adenoide, Gra- 
tiolet’s membrane glanduleuse) is the next outer layer. It con- 
sists of a wide-meshed framework of connective tissue, the 
meshes containing the gland alveoli. A few nerve trunks are 
met with amongst these latter in some places: from the caver- 
nous layer extend small bundles of unstriped muscle tissue 
amongst the alveoli in some places; a similar arrangement has 
been pointed out by me (see October number 1880 of this Journal), 
also for the glands of other parts of the nasal organ. This 
layer is thickest at the lower sulcus, where its diameter amounts 
to 0°22—0°28 mm. ; here it occupies at the same time the whole 
thickness of the wall, there being here no cavernous layer. In 
about the middle of the lateral wall the thickness diameter of 
the gland layer is about 0°08 mm. It decreases towards the 
upper sulcus, where it becomes reduced to a single layer of 
alveoli. 
In those places where the cartilage capsule is incomplete the 
glandular layer is on the whole much better developed than 
where this is not the case. 
The gland alveoli are not confined to the lateral wall and to 
