_1_, Apex; _2_, dorsum; _3_, root; _a_, orifices of ducts of lingual
glands; _b_, papillæ of root; _c_, vallate papilla (not really so
distinct as in figure); _d_, foliate papilla; _e_, fungiform
papillæ; _f_, epiglottis (pulled back); _g_, median
glosso-epiglottic fold. (Ellenberger-Baum, Anat. _d_. Haustiere.)
]
The =tongue= is long and narrow and the apex is thin. Two or three
vallate papillæ are present. The fungiform papillæ are small and are
most numerous laterally. The filiform papillæ are soft and very small.
On the root there are soft, long, pointed papillæ, directed backward.
Foliate papillæ are also present.
There is a well-marked median glosso-epiglottic fold, on either side of
which is a depression (Vallecula epiglottica). The frenum linguæ is
double.
The =dental formula= of the pig is:
( 3 1 4 3 )
2 ( I - C - P - M - ) = 44
( 3 1 4 3 )
The formula for the temporary teeth is:
( 3 1 4 )
2 ( Di - Dc - Dp - ) = 32
( 3 1 4 )
The =upper incisors= are small; they are separated from each other by
spaces, and from the canines by a larger interval. The first incisors
are the largest, are convergent, and have no distinct neck. The second
are narrower and somewhat smaller. The third (corner) incisors are much
smaller, are flattened laterally, and have three small eminences on the
crown.
The =lower incisors= are almost horizontal and are convergent and close
together. The first and second are about equal in size, prismatic, and
deeply implanted in the jaw. The labial surface is slightly convex, the
lingual concave and marked near its extremity by a ridge. The third
incisor is much smaller and has a short narrow crown and a distinct
neck.
[Illustration:
FIG. 308.—SKULL OF PIG ABOUT A YEAR AND A HALF OLD, SCULPTURED TO SHOW
THE EMBEDDED PARTS OF THE TEETH.
_I1–3_, Incisors; _C_, canines; _P1–4_, premolars; _M1–3_, molars.
]
The =canine teeth= or tusks of the male are greatly developed and
project out of the mouth. The upper canine of the boar may be about
three or four inches (ca. 8 to 10 cm.) long. The crown is conical and is
curved somewhat backward and outward; the embedded part is curved and
has a large pulp cavity.[111] The lower canine may reach a length of
eight inches or more (ca. 20 cm.); the crown is prismatic and is curved
backward and outward in front of the upper one, so that the friction
between the two keeps a sharp edge on the lower tooth. In the sow they
are much smaller.
[Illustration: