172 
MR. W. K. PARKER OK THE STRUCTURE AND 
three trabecular bars—the trabeculae right and left, and the intertrabecula above, 
the fore edge of the alisphenoid is not yet reached, but the fore part of the Gasserian 
ganglion (V.) is shown. On the side of the wide, oblong nasopalatine canal (n.p.) 
the pterygoid bone and cartilage {jpg., pg.c.) are cu f across > and below we have still 
the dentary with Meckel’s cartilage ( mk .), and also with the superficial cartilage that 
forms the condyloid and angular regions ; the ceratohyals (c.hy) are also seen in this 
section. 
13 th Section (Plate 24, fig. 2). — This partial section shows the orbitosphenoid (o.s.) 
in two parts, the postero-superior band, and the hind margin of the stem ; the basal 
part (p.s.) is fusiform. Below the stem of the orbitosphenoid, at a considerable 
distance, the alisphenoid ( al.s .) is seen as a thickish plate, curved downwards, and 
beaded at its outer edge. Its concavity makes a nest for the large Gasserian ganglion 
(V.), which is protected above by the orbitosphenoid. Two thick rods of cartilage 
are cut through between the alisphenoids, one on each side of the broad nasopalatine 
passage, they turn inwards and downwards, and are capped with a film of bone 
above, these are the pterygoid cartilages, with the growing pterygoid bones (see 
fig. 3), Below we see the mandible as one large folded tract of bone (d.) embracing 
three cartilages; the middle of these is the Meckelian rod (mk .), the others are the 
condyloid and angular parts of the superficial slab. Below 7 the oral cavity (in.) the 
ceratohyals {c.hy.) are seen. 
14 th Section (Plate 23, fig. 4). — Here the same parts are better seen, than in the 
last, in a more symmetrical figure. 
15th Section (Plate 24, fig. 5).—Here only the posterior band of the orbitosphenoid 
{o.s.) is seen, for the basal part ( b.s.) now runs into the alisphenoid {al.s.), which is 
cut through proximally, at its postero-external angle. The Gasserian ganglion ( V.) 
still lies on it, at its proximal part, the cartilage dipping considerably to form a 
nest for it. Here the basisphenoid {b.s.) is formed of the outspread and coalesced 
trabeculae, this part being somewdiat in front of the pituitary space. The squamosal 
{sq.) is seen outside the angle of the alisphenoid, and Meckel's cartilage {mk), 
the latter, the end of the angular, and part of the articular cartilage {inn.), are also cut 
across. 
There are three cavities laid open, namely, the nasopalatine {n.p.c.), the mouth (m.), 
and the larynx {lx.) ; the Eustachian tubes are also laid open in their inner half, 
continuously with the nasopalatine passages. Besides the cartilage of the larynx, the 
epihyal, and hypohyal {c.hy., h.hy.), are cut through. 
16 th Section (Plate 25, fig. 6).—This is from a little further backwards than the 
last, and takes in part of the meatus auditorius externus, with its lining cartilage 
{m.a.c.). This partial section is below the orbitosphenoidal band, and behind most 
of the alisphenoid {al.s.) ; outside the proximal part of that wing, which is cut through 
below the Gasserian ganglion (V.), Meckel’s cartilage {mh.) is seen high in position, 
and large in size. The Eustachian tubes {eu.) are laid further open than in the last 
