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550 DR. E. KLEIN, 
organ of Jacobson is easily perceived as a bilateral tubular bulg- 
ing, extending in the septum along the lower nasal furrow. 
The outer wall of each organ or tube, 7.e. the one actually 
seen—the other, or median wall, being hidden in the septum— 
is marked by its rich supply of large blood-vessels, constituting, 
as will be mentioned below, the cavernous layer of the tubes. 
The length of the tubes in a medium-sized rabbit is from 1°5 
to 2 centimétres, and already with the unaided eye it can be 
ascertained that each tube rather sharply tapers towards its ante- 
rior and posterior extremity. 
Making transverse sections through the front part of the nasal 
organ, the following cartilages are met with :— 
1. The cartilage of the septum. ‘This is hyaline cartilage, 
staining deeply in logwood, except the part next to the dorsum 
of the nose, this part being triangular in section, and not 
staining well in logwood. Between the two divisions there is 
this great difference: that in the former the cartilage cells are 
very much closer in position than in the latter, they being here 
arranged more distinctly in groups of two, four, six, or eight cells, 
separated by relatively large masses of hyaline ground substance. 
In logwood-stained specimens the hyaline matrix, as well as the 
cells, are very slightly stained in the upper part, whereas they 
assume a deep colour in the lower part of the septum. In both 
divisions, but especially in the upper one, the cartilage cells con- 
tain in their substance several small oil globules or one large oil 
drop. Next to the perichondrium, the cartilage cells are small, 
flattened parallel to the surface, whereas in the centre of the 
cartilage the cells, or rather their groups, are arranged more or 
less transversely ; a similar distinction, as is well known, F. HE. 
Schultze,! has noticed in the bronchial cartilages. 
The close position of the cells in the lower part and the deep 
staining of this latter, appear to indicate that a more active growth 
is taking place in it than in the upper portion of the septal 
cartilage. 
This cartilage increases in height and thickness, especially its 
lower margin becomes conspicuous by its enlargement, as we 
pass backwards in the region of the organ of Jacobson. 
2. The cartilage of the lateral wall. A transverse section made 
in the region of the incisors, shows us on each side in the lateral 
wall of the nasal cavity, rising from the lower nasal furrow, and 
forming the support of that wall, a cartilage plate, extending with 
a somewhat broad projection into the front or smooth part of 
the lower concha. In connection with it is a thin cartilage 
plate, extending laterally and upwards in a curved manner. In 
fig. 1 these cartilages are well shown. ‘The first, i.e. the one 
1 ‘Stricker’s Manual of Histology,’ article ‘‘ Bronchi and Lung.” 
