APPENDIX No. II. 
51 
resting upon the skull ; there is also a cavity in the bone adapted to receive them. The bags vary in size in 
the different species of these genera. The French naturalists have given the name of larmiers to these 
bags, conceiving them to be receptacles for the tears, of which the thinner parts evaporating, a substance 
remains called larmes de cerf. 
I requested my friend Mr. Andre to examine these bags in the common buck, and to observe their rela- 
tive position to the puncta lachrymalia ; his situation in the Earl of Egremont’s family at Petworth afford- 
ing him every opportunity for doing it. He informs me that the bags are lined with a cuticle similar to 
that of the meatus auditorius externus in the human ear ; their internal surface is smooth, free from hair, 
and without any appearance of glandular structure. From the inner angle of the eye to this bag, there is a 
kind of gutter in the skin, of a darker colour than the rest of the skin in light coloured animals, and the hairs 
are shorter than on the rest of the body : the substance contained in the bags resembled that found in the 
ears. 
The lachrymal gland in the deer, he says, is very large, and the puncta so much so, as to admit the 
rounded end of a common probe. There is no lachrymal sac ; the tubes from the puncta unite and pass 
through a small opening in the bone to the nose. 
The following account of these bags, in the Antelope of Sumatra, was transmitted to me in the year 1 792, 
by Mr. Bell. “ The external orifice is of the size of a crow quill ; it leads into a bag not larger than a 
“ small marble, which is lined with a cuticle with hair. From this bag there is a secretion of a limpid fluid, 
“ which keeps oozing down the nose.” This gentleman, unfortunately for Natural History, died at Sumatra 
soon after the date of his letter. 
In the Hunterian Museum, intrusted by Government to the care of the College of Surgeons, there are 
several specimens of these bags from the Egyptian Antelope, with annulated horns, and also from some 
other species ; these are preserved so as to shew the internal cavity of the bag, and the structure of the 
gland immediately behind it. In these specimens the glandular part is one-fourth of an inch in thickness; 
from the centre of this gland, an excretory duct opens into the bag immediately opposite to the external 
orifice. The bag itself is lined with a cuticle, and thinly set with strong hairs. 
The facts now produced are sufficient to prove that these bags have a secretion of their own, the quantity 
of which varies according to the climate and other circumstances ; and there is no reason for thinking that 
the tears ever pass into them, the passage into the nose being unusually free, and the orifices in the bags in 
many species unfavourably situated for the reception of the tears. 
We are at present unacquainted with the use to which the fluid secreted in these bags is applied. 
As amphibious animals, in general, have no glands to supply the skin with moisture from within, but 
receive it by coming in contact with moist substances, it is possible the bags in the snake may be supplied in 
that manner, and the more so, as the cuticular lining appears perfect. 
Another peculiarity is remarkable in snakes furnished with the bags described above, namely, an oval 
cavity situated between the bag and the eye, the opening into which is within the inner angle of the eyelid, 
and directed towards the cornea. In this opening there are two rows of projections which appear to form 
an orifice capable of dilatation and contraction. From the situation of these oval cavities, they must be con- 
sidered as reservoirs for a fluid, which is occasionally to be spread over the cornea ; and they may be filled 
by the falling of the dew, or the moisture shaken off from the grass through which the snake passes. 
This apparatus in the snake has that position which is best adapted to pour out the fluid upon the cornea, 
when the head of the snake is erect. 
Dr. T yson had superficially observed the apparatus which has been described, and considered it as a 
membrana nictitans. He says, “ inwards it seemed to have a membrana nictitans, which removes any dust 
61 that might adhere to the eye.”* 
* Phil. Trans, vol. xiii.p. 27". 
