Mr. Bell on the structure and use, &c. 133 
extended our information on some of the most intricate 
subjects of comparative anatomy and physiology — the result 
principally of a minute examination of individual and peculiar 
structures. I make no apology therefore for the following 
short communication, to which the foregoing observations 
are, to a certain extent, applicable. 
It has long been known, that beneath the lower jaw of the 
alligator and crocodile, there is situated, on each side, a 
gland, the office of which is to secrete an unctuous substance, 
having a strong musky odour : but although anatomists have 
not been ignorant of the existence of such a gland, our infor- 
mation has hitherto rested here, whilst its structure, and the 
apparatus connected with it, appear not to have been inves- 
tigated, nor has any probable object of such a formation 
been suggested. In a careful examination however of this 
remarkable organ, which I made about two years since, I 
discovered a peculiarity of structure, which, as far as I have 
learnt, is without a parallel in the glandular system of ani- 
mals, unless, as Sir Everard Home has kindly suggested, 
the muscle, which is described by Dr. Russell* as governing 
the poison gland in serpents, may be considered as in some 
measure analogous. The description of this structure, with 
which repeated subsequent dissections have made me more 
particularly acquainted, I now have the honour to submit to 
the Royal Society. 
It is necessary to premise, that my observations have 
hitherto been confined to the common alligator of America. -f 
The external orifice of the gland, through which the secre- 
* Ind. Serp. vol. i. p. 90. t. 46. 
f Crocodilus Lucius. Cuv : 
