220 DR. E. KLEIN, 
being now found in the guinea-pig! there is of course no 
difficulty whatever in ascribing to the organ of Jacobson in this 
animal a function similar to that of the oliactory mucous 
membrane, but probably of a more specific nature, as I have 
already hinted at in my last communication. Whether in 
other mammals this communication with the nasal cavity 
persists, will be a subject to which I soon hope to devote 
myself. 
Examining a series of vertical transverse sections through 
the front part of the nasal organ of the guinea-pig, the 
organ having been previously suitably prepared (see my 
paper in this Journal for January, 1881), we meet with ap- 
pearances of the several parts, very accurately shown in the 
figures 1 to 6 of Plates XVI and XVII. 
Fig. 1 is a transverse section through the most anterior 
part of the nasal organ. The relation of the cartilaginous 
septum to the lower turbinated bone, or lower concha nasalis, 
and further, of this to the alveolar process of the superior 
maxilla, are very well illustrated, the drawings being all made 
with the camera lucida, the relative proportions and sizes 
are all very accurately preserved. It will be seen in fig. 1 
that the cartilaginous septum nasale forms an unbroken 
continuity with the cartilage representing here, 2. e, in the 
front part of the nasal organ, the support of the lower 
concha. This continuity is brought about, on each side, 
by a curved, more or less trough-shaped cartilage plate ex- 
tending on the inner surface of the alveolar process of the 
superior maxilla to the angular piece of cartilage that forms 
the support of the lower concha. But this continuation is 
more or less broken as we pass a little way backwards 
(see fig. 2). Here we find the above-named curved car- 
tilage plate more or less separated from the lower margin 
of the septum as well as from the cartilage piece of the 
concha. 
In my former communication I have used the term 
*‘concha” of the German anatomists for the “ turbinated 
bone” of English text books. I consider the former term 
preferable, because it gives to the organ a name indepen- 
dent of its structure. In our case, z.e. in the front part of 
the nasal organ where there is no bone contained in it yet, 
it would be incorrect to speak of a turbinated ‘ bone.’ 
In fig. 3, which is taken a little behind fig. 2, this sepa- 
ration is complete, and, in addition, we find also the carti- 
1 T am ina position to assert also for the rabbit such a free communi- 
cation of the organ of Jacobson with the nasal cavity. 
