r
n o EX P L A N A T I O N OF THE TABLES.
C, A fi-Knnm fixed above a chink between two ligamento-cartilaginous bodies
D and E. Thefe bodies refemble the human epiglottis, and the frffinum is lilce
the membrane which ties the epiglottis to the tongue.
F G, Two large facs fcparated from each other by the frajnum. The right
fac is laid open, and a probe is paffed into the left one. The membrane lining
thefe facs is of the fame colour, and has the fame kind of folds or valves, as
Were feen at B. Thefe facs coniiitute the organ of fmell.
H, A thimble-likc cavity, lined with a thin fmooth membrane, under the
right fide of the epiglottis, or rather under the right epiglottis.
I K , Probes paffed into the right and left noftrils or air-paffages, wliich are
divided from each other by a feptum L.
F I o. 4.
THIS Figure iliows the continuation of the fpiraculum or air-paffage and the
larynx, after cutting open the mouth and throat on the right fide, and inverting
the head.
A , The edges of the tongue ferrated.
B, The upper furface of the tongue.
C , The top of the larynx; the upper part of which confifts of one cartilage,
but the under part is compofed of two cartilages.
D , A mufcle for fliutting the top of the larynx.
E F, Two mufcles for opening the larynx.
G> The right fide of the larynx is cut into, to fliow G, a ligament in the
middle of its under part.
H, The termination of the fpiraculum, over the mouth of the larynx, furrounded
by a mufcle L
K, The right fide of the fpiraculum cut open, to fliow the back part of the
feptum K.
L M , The lower ends of the two probes, feen in fig. 3. at IK.
N, A cylindrical tube from K to H.
O, A probe put into the mouth of the right Euftachian tube, or iter i palato
ad aurem.
F i g . 5.
THIS Figure fliows the outfide of the os petrofum, with the meatus auditorius
externus and the Eufl:achian tube laid open their whole length.
F, The entry to the meatus auditorius externus.
G, The meatus auditorius externus laid open its whole length, and crooked
at its back part G.
H, The
E X P L A N A T I O N OF THE T A B L E S . ' 11 1
H, The outfide of the os petrofum; the point of which, H, refembles our
mailoid procefs.
I, The membrane of the drum, concave on the outer fide.
K, The right nollril cut farther open, to ihow L, the mouth of the Euftachian
tube.
M, The Euftachian tube laid open from its origin to its termination within
the car or os petrofum at N . It is gradually enlarged in its courfe from the
nofe to the ear.
F I G. 6.
THE inner fide of the os petrofum H, and of the adjoining bones being cut
away, this, figure reprefeats the cavity of the tympanum, its contents, and
the parts with which it communicates.
I, The bottom of the meatus auditorius externus, and membrana tympani
concave on the outer fide.
K L, A red-coloured fubftance and chain of fmall bones, by wliich the membrane
of the drum is drawn inwards, and connected to the bottom of the cavity
of the tympanum.
M, A fmall mufcle fixed to the laft of the finall bones, refembling our Itapes
and its mufcle. . . ..
N, A probe paffed from the Euftachian tube into ^ e cavity of the tympa*
num. • -- -
O, A fubftance within the os petrofum or cavity of the tympanum, which in
lhape refembles our os fpongiofum inferius.
P, A large paffage kading from the cavity of the tympanum forwards to caverns
Q^ and R ; the latter of wliich leads to the frontal iinus.
F I G. 7.
Rcprefents the inner fide of the os petrofum S, with the auditory nerve T
entering it.
F i g . 8.
Rcprefents the inner part of the os petrofum; from which the auditory nerve
and part of the fubftance of tlie bone are cut off, in order to ftiow the holes by
which the nerves enter, and part of the cochlea and femicircular canals.
S, The inner fide of the os petrofum,
U V , The holes by which the branches of the auditory nerve enter.
W , A fmall portion of the cochlea cut open.
X , One of the femicircular canals cut open.
F I G .
I I J
m istil