278 COMPARATIVE ANATOMY AN1) PATHOLOGY. 
oils follicle beneath his eye formed so striking a feature in the 
animal’s physiognomy. It never appeared as a simple slit, but its 
thickened edges pouted so widely as to be at all times partially 
everted. When he was excited — and he was at all times highly 
excitable — the eversion of the bag became complete, and its thick 
lips being thrown widely back, the intervening space was actually 
forced forward so as to form a projection instead of a hollow. The 
animal on such occasions delighted to thrust repeatedly the naked 
lining of the sac against any substance that was offered to him, 
and that soon became loaded with a dark-coloured secretion of 
ceruminous matter, having a slightly urinous or sexual odour. 
There was an emasculated individual of the same species, of full 
growth, in which this suborbital sinus presented nothing but a slight 
fissure, the edges of which were closely applied to each other, and 
never appeared to be moved. Messrs. Owen and Ogilby, both of 
high authority on such a subject, expressed the same opinion, and 
a letter was read from Mr. Hodgson, of Nepal, a corresponding 
member of the society, in which the same hypothesis was main- 
tained and incontrovertibly proved by the various appearance of the 
gland and its secretion at different times*. I am not wandering far 
from my subject; for although I deny that this apparatus is connect- 
ed with the organ of smelling in the animal who possesses it, it 
secretes a substance, by the diffused odour of which the purposes 
of nature are accomplished. 
I have hitherto been speaking of the herbivorous quadrupeds : 
we now turn to the carnivorous ones. 
The Dog . — I select this animal from among the predaceous ones 
because he comes under our daily observation — he is our com- 
panion as well as our slave. The olfactory organs of the animals 
that have hitherto passed in review enable them to distinguish ve- 
getable odours, and, so far as we have the opportunity to observe, 
those alone ; except such other emanations as are connected with 
the great law of nature. Their food usually presents itself when- 
ever they go, and all that is required is to select the nutritive from 
the poisonous. It is not so with carnivorous animals. Their 
prey has no fixed situation. It is here at one minute, and, at the 
next, frightened by the approach of the destroyer, it is fleeing far 
away. The organ of sight would rarely serve for the discovery of 
its track. It is, therefore, necessary that the olfactory organs of the 
carnivora, should be “ sensible to the weak impressions of parti- 
cles widely diffused through the surrounding medium, or slightly 
adhering to those bodies with which the object of their pursuit 
Proceedings of the Zoological Society, March 22, 1836. 
