THE ORGAN OF JACOBSON IN THE RABBIT. 569 
subepithelial layer, extend into the epithelium in many places in 
a more or less uniform manner. ‘This is evidently analagous to 
the fact described of the naso-lachrymal duct of the guinea-pig, 
viz. an extension of capillary blood-vessels and nucleated cells 
from the subepithelial layer into more or less well defined cavi- 
ties in the epithelium. In the rabbit the intraepithelial spaces 
containing the capillary blood-vessels and lymph-corpuscles do 
not appear to be of this same well-defined nature. 
3. Outside the subepithelial layer is a plexus of smaller and 
larger veins, running chiefly in a longitudinal direction, and a 
few arterial branches also extending in a longitudinal direction. 
The tissue in which these vessels are embedded is a very loose 
connective tissue infiltrated with numerous lymph-corpuscles. 
As was pointed out in my former paper, Henle! already de- 
scribed the occurrence of lymphatic tissue in the wall of the 
naso-lachrymal duct of man. 
The last point that I wish to describe here are the structure 
of the mucous membrane lining the lower nasal furrow, and 
covering the inferior turbinated bone, and the nasal septum in 
the region of the organ of Jacobson. 
In the most anterior portion of the nasal cavity, anterior to the 
part illustrated in section, fig. 1, the epithelium covering the free 
surface of all the above regions, viz. the nasal furrow, turbinated 
bone, and nasal septum, is stratified pavement epithelium ; the 
subepithelial connective tissue is infiltrated in many places with 
lymph-corpuscles ; rudiments of papillee are present in the region 
of the lateral wall of the nasal furrow. 
The mucosa contains serous glands only over the inferior 
concha. But there is everywhere an indication of venous plexuses, 
situated in the superficial part of the mucosa, and extending 
more or less parallel to the long axis of the nasal organ ; these 
plexuses are well developed in the upper part of the septum and 
in the inferior concha. 
A little further behind, e. g. in fig. 1, the epithelium lining the 
nasal furrow and the nasal septum is still stratified pavement 
epithelium, but the epithelium covering the surface of the infe- 
rior concha is already stratified columnar, the superficial cells being 
ciliated. Numerous serous glands in the deeper layer, and very 
rich plexuses of venous vessels in the superficial layer, are con- 
tained in the mucosa of the inferior concha, and in a limited 
degree also in the mucous membrane of the nasal septum. 
In a place, of which fig. 2 is a representation, the lower nasal 
furrow alone is lined with stratified pavement epithelium, all the 
' « Hingeweidelehre,’ ii, p. 713. 
