110 DR. E. KLEIN. 
into the epithelium has been described by Professor Lankester! in 
the integument of the medicinal leech. 
Outside the epithelium is a fibrous coat, whose thickness in 
the lateral and median wall is about the same, 0°05—0°06 mm. 
It contains minute nerve-bundles, and eapillaries are found only 
immediately underneath the epithelium. In the lateral wall 
there are several arterial vessels running longitudinally ; where 
the organ is in contact with the bone (see fig. 1), the fibrous 
coat is in intimate connection with the periosteum. In the 
lower part of the median wall, z.e. the one in contact with the 
mucous membrane of the descending inner surface of the concha 
(see fig. 1), the mucous membrane is more or less distinctly infil- 
trated with lymph-cells similar to that of the concha. At the 
upper and lower sulcus the tissue is very loose, and contains, as 
mentioned previously, large blood-vessels running in a longitu- 
dinal direction ; the diameter of the largest vessels here is about 
0-13 mm. Numerous elastic fibrils, extending longitudinally 
and connected into a network and flattened connective-tissue 
cells, each with an oval nucleus as well as a few minute nerve 
branches, are also to be met with here. 
1G EP: 
The mucous membrane covering the cartilaginous septum 
and lining the furrow between the septum and the alveolar 
process of the superior maxilla in the region of the organ of 
Jacobson has the following structure :—Both surfaces of the car- 
tilaginous septum are lined with an epithelium of exactly the same 
nature as that described above as lining the lateral wall of the 
_organ of Jacobson, viz. stratified columnar epithelium, of which 
the most superficial cells are conical and possessed of cilia. 
Goblet cells occur also here. 
The thickness of the whole epithelium is about 0°056—0:07 
mm., the length of the cilia 0:006 mm. 
The mucous membrane immediately underneath the epithelium 
is fibrous connective tissue, infiltrated in many places with lymph- 
corpuscles. A network of venous vessels in the mucous mem- 
brane forms a very conspicuous feature. 
The mucous membrane of the septum is thickened at three 
definite places, owing to the presence of glands; these places 
are: a, where the septum joins the dorsum of the nose; 4, in 
about the middle height of the septum; and ec, at the point 
where the thick rounded lower margin of the cartilaginous 
septum is fixed on the cartilage of the organ of Jacobson. In 
Plate VII, fig. 1, these places are easily recognised. At the last 
place the thickening is greater than at the second, and at this 
1 This Journal, No. 79, New Series, p. 303. 
