in North-Western America. Mr. Washington Matthews Assistant-Surgeon
in the United States Army, also observed with special care
(after having seen my queries, as printed in the `Smithsonian Report')
some of the wildest tribes in the Western parts of the United States,
namely, the Tetons, Grosventres, Mandans, and Assinaboines;
and his answers have proved of the highest value.

Lastly, besides these special sources of information, I have collected
some few facts incidentally given in books of travels.--------


As I shall often have to refer, more especially in the latter part
of this volume, to the muscles of the human face, I have had a diagram
(fig. 1) copied and reduced from Sir C. Bell's work, and two others,
with more accurate details (figs. 2 and 3), from Herde's well-known
`Handbuch der Systematischen Anatomie des Menschen.' The same letters
refer to the same muscles in all three figures, but the names are given
of only the more important ones to which I shall have to allude.
The facial muscles blend much together, and, as I am informed,
hardly appear on a dissected face so distinct as they are here represented.
Some writers consider that these muscles consist of nineteen pairs,
with one unpaired;[20] but others make the number much larger,
amounting even to fifty-five, according to Moreau. They are,
as is admitted by everyone who has written on the subject,
very variable in structure; and Moreau remarks that they are hardly
alike in half-a-dozen subjects.[21] They are also variable in function.
Thus the power of uncovering the canine tooth on one side differs much
in different persons. The power of raising the wings of the nostrils
is also, according to Dr. Piderit,[22] variable in a remarkable degree;
and other such cases could be given.