106 DR. E. KLEIN. 
while the bodies of the sensory cells appear larger than those 
of the olfactory cells. 
Balogh? describes the epithelium of the organ of Jacobson of 
the sheep, without, however, making a distinction between the 
sensory epithelium lining the median wall and the ciliated epi- 
thelium lining the lateral wall. According to this observer the 
epithelium consists of two kinds of cells—(a) large ciliated 
columnar cells, and (2) smaller olfactory rods (Riechstibchen). 
These latter are rod-like, hyaline, and contain in their lower or 
deeper part a swelling produced by the nucleus. They extend 
to the free surfaee, and possess here two triangular pointed rods 
(Riechhirchen). 
Balogh says that he has convinced himself of the connection 
of the epithelial cells with the processes of the connective-tissue 
corpuscles of the mucosa, while the ‘‘ olfactory rods” are con- 
nected, through spindle-shaped cells, with the olfactory nerves. 
But, considering the methods with which he worked (macera- 
tion in acetic acid mixture) it 1s not too much to say that these 
assertions must be received with great reserve. 
I cannot say precisely what the function of the organ of 
Jacobson is, since I have not made any experiments on this 
point. Kdlliker? thinks that “if we do not assume that the 
tubes of Jacobson are simply secretory organs, their vascular 
thickness, their numerous glands, and the numerous branches of 
the nervus naso-palatinus, seem to point to it; but against this 
speaks their supply with very numerous olfactory nerve-fibres. 
There remains nothing else but to assume that they (Jacobson’s 
tubes) secrete yuices and substances which act on their specific 
nerves, and thus enable the organism, directly, as it were, to 
obtain knowledge of the chemical constitution of its own juices.” 
Whatever may be the precise meaning of this view of Kolliker’s, 
it seems strange to have recourse to such a theory. Why should 
it not serve for the perception of specific smells, seeing that it 
really belongs to the olfactory nerve termination? Its commu- 
nication with the oral cavity does not appear to me to be adverse 
to such an assumption. 
In man the organ of Jacobson is only of a rudimentary 
nature (Kolliker) as compared with that of mammals, and do 
not these latter possess a power of perception of smell, about the 
degree and nature of which human beings can hardly have a true 
conception ? 
1 Loe. cit., p. 465. 
+ Dog. Cites ps LL. 
