414 APPENDIX. 
mal. Camper found a membranous cist on the Reindeer above the thyroid 
cartilage, and opening into the larynx, but I have met with no account of a 
cist with a duct opening externally like that described by Mr. Hutchins, and, 
unfortunately, I was not aware of his remarks until the means of ascertaining 
whether such a sac exists in the Barren-ground Caribou were beyond my 
reach.” : 
Mr. Morrow had several times looked for the cyst without success, but always 
forgot to do so for the sac; and, in order to obtain some information on both 
points, he went to the woods in December last, and succeeded in killing a large 
buck, the result of the examination of which, and dissection of others, male 
and female, made since, he would place before the Institute. But first, he 
thought it necessary to give Camper’s description of the membranous sac from 
a Reindeer “four years old.’ Camper says,! ‘‘ that as he did not know the 
Reindeer, and as the imperfect account which Valentyn gave of Stenons’s dis- 
section in 1672, did not give him much light, he was forced to proceed with 
caution (date, June, 1771). He had often observed in the bucks, that when 
these animals swallowed, all the larynx rose and fell in a peculiar manner, and 
seemed to indicate something singular in this part. He then removed the skin 
of the neck with much care. The muscles being raised in the same way, he 
found a membranous sac, which had its origin between the os hyoides and the 
thyroid cartilage. He then discovered two muscles, which take their origin from 
the lower part of the os hyoides, exactly where the base of the os graniform and 
the cornua meet. These muscles were flat and thin at their beginning, but 
widened towards their junction with the sac, and certainly served to support it 
as well as to expel the air from it at the will of the animal. After he had opened 
the esophagus from behind, he found under the base of the epiglottis a large 
orifice which admitted his finger very easily. This orifice spread, and formed 
a membranous canal, which passed between the two muscles already men- 
tioned, terminating in the membranous sac. Consequently the air driven from 
the lungs into the larynx fell into this sac, and necessarily caused a consid- 
erable swelling.’’ 
Mr. Morrow said that when he shot the buck alluded to, he had not seen the 
account by Camper of the sac, and his specimen is not therefore so perfect as it 
might otherwise have been. Examining the outside of the throat of the animal 
the cyst of Mr. Hutchins, with ‘an opening through the skin,’’ does not exist; 
but immediately under the skin, there was a roundish sub-triangular cyst or 
valve of cellular membrane of the ‘‘ bigness of a crown piece,”’ and on cutting 
through the cellular membrane, this “ valve” is found to be a closed sac hav- 
ing a peculiar lining membrane, and closely packed with what may be called 
loose hairs of a flaxen color, in a considerable quantity of sebaceous matter ; 
at the same time, however, the lining membrane is covered by hairs of the same 
quality growing from and rather lightly attached to it. Camper in his account 
has described this valve as if it were the sac, and his drawing gives only the 
valve, which the larynx exhibited by Mr. Morrow plainly shows. The muscles 
which Camper describes as connecting the sac with the os hyoides, in Mr. 
Morrow’s specimen do not exist, but their representatives are probably the 
muscles found in the larynx of the young buck by Dr. Sommers, as will later 
appear. The valve is connected with the omo-hyoid muscles as they pass to- 
1 Camper, vol. i., chap. vi., page 338, Paris, 1803, where reference is made by let- 
ters to a plate, which cannot be done here. 
