628 
MR. W. K. PARKER OK THE STRUCTURE AND 
Under the down-turned nasal septum, this section shows the internal nostril (i.n.), 
and behind it we see the palatine thickening and the maxillary wall. 
A series of delicate sections'”' (transversely vertical) show many other details of the 
structure of the skull at this stao-e. 
o 
The 1st section (Plate 39, fig. 4), ls in front of the eyes, but behind the nasal roof; 
the septum ( s.n .) is shown; also the nasal passages, largely occluded by the inferior 
turbinals and glands ; and the fore part of the long hemispheres (C la ). 
The 2nd section (fig. 5) is through the front of the eye-ball, and the lowest part 
of the septum; the long orbito-sphenoidal cartilage (o.s., seen also in fig. 3, from its 
inside,) is cut through its fore end. 
The 3rd section (fig. 6) is through the wider part of the hemispheres and of the 
orbito-sphenoids (C la , o.s.); the tissue in the severed ridges, below, becomes, by direct 
ossification (without cartilage), the palatines and maxillaries. 
This section shows the depth of the supercranial valleys, and the height of the eye¬ 
balls, equal to that of the hemispheres; here the orbital septum is thick, before the 
ethmoid ( p.e .) passes into the presphenoid. 
The Ath section (fig. 7) is through the widest part of the eyes, the hemispheres, 
and of the orbito-sphenoids, and the highest part of the orbital septum (C ]fl , o.s.,p.e.); 
here the mandible and Meckel’s cartilage (ran., ML), are also severed ; at this part 
the trabeculae are becoming distinct, below. 
The 5 tli section (fig. 8) is between the eyes and the ears; it shows, very distinctly, 
the pituitary body {py.) as a distinct vesicle, lying under the infundibular region of 
the fore brain. 
This section takes in the hind part of the hemispheres (C la ), where they join on 
to the mid brain (C 2 ) above, and to the “ thalamencephalon ” (C 1 ) below. 
Here the trabeculae (tv.) are widest apart (see fig. 2) ; they are oval in section, being 
flattened, and not circular as in the Snake. 
The wall of the skull is membranous below, but higher up, the stem and part of the 
lower bar of the alisphenoid (ais.) are cut down obliquely, as they run into each other. 
Outside the trabeculae we see the superadded cartilages of the pterygoid region of the 
mandibular “pier,” namely, the ascending or “ epipterygoid” rods ( e.pg .), with a 
“foot ” of cartilage lying against the trabecular meniscus. These will be well under¬ 
stood by reference to what I have described in the adult (Plate 43). 
The whole of the epipterygoid (e.pg.) is not shown, the top was shaved off obliquely; 
it must be supposed to ascend one-thud higher. 
Below, and on each side of the mouth ( mi ), we see Meckel’s cartilage, the cerato- 
hyal, the cerato- and hypo-branchials, and the trachea (Aik. , c.Jiy., c.br., h.br., trc.). 
The 6th section (fig. 9) is through the brain where the optic lobes (C 2 ) rest upon the 
* These sections, stained with “eosin,” and mounted as transparent objects, were made for me by my 
friend, Patrick Geddes, Esq., and my son, Mr. W. N. Parker. 
