570 DR. E, KLEIN. 
other parts with stratified columnar cells, of which the super- 
ficial layer is made up of ciliated cells, with the usual goblet 
cells amongst them. The subepithelial layer contains numerous 
lymph-corpuscles and a rich plexus of veins; the deeper layer 
of the mucosa includes serous glands, forming a continuous 
layer in the mucous membrane of the lower concha and in that 
of the upper part of the nasal septum ; but they are scarce in 
the lower part of the latter, and are altogether absent in the 
mucous membrane of the lower nasal furrow. 
The same relations obtain past the mouth of Jacobson’s organ 
until the part is reached which is illustrated in fig. 4, ze. 
showing Jacobson’s cartilage a closed capsule, except that the 
mucous membrane covering the lower part of the nasal septum 
contains very numerous serous glands; the epithelium lining the 
lower nasal furrow is still stratified pavement epithelium. 
A little further back, viz. where Jacobson’s cartilage has 
assumed the shape of a trough (see figs. 5 and 6) with a long 
median labium, also the epithelium lining the lower nasal furrow, 
i.é. the concave surface of Stenson’s cartilage, is stratified columnar, 
the superficial cells being ciliated, with the usual goblet cells 
amongst them. 
The thickness of this ciliated columnar epithelium is the 
same as in other parts of the nasal cavity, and amounts 
to about 0°:086 mm., exclusive of the cilia, which are about 
00072 mm. long. 
The serous glands in the mucosa of the lower part of the nasal 
septum have now greatly increased, and, as has been pointed 
out before, form a continuity with the glands of the organ of 
Jacobson. ; 
Of interest is the occurrence of diffuse adenoid tissue, and of 
smaller and larger lymph follicles, isolated and in continuous 
patches in the mucous membrane lining the concave side of 
Stenson’s cartilage, as is shown in figs. 6 and 7. 
The diameter of a well-defined lymph-follicle of the larger kind 
varies between 0°216 by 0°25 mm., and 0°3 by 0°45 mm. 
The extension of the adenoid tissue of these lymph-follicles 
into the epithelium of the surface is the same as described above 
of the lymph-follicles of the naso-lachrymal ducts. 
