G02 
MR. W. K. PARKER OK THE STRUCTURE AHD 
arch”; even in the Axolotl (Phil. Trans., 1877, Plate 24, tigs. 1-3) there is only a small 
proximal, and a small distal, cartilage (the “ ethmo-palatine ” and “ post-palatine ” 
cartilages), whilst the symplectic outgrowth of the suspensorium is very large. 
Here, in Lacerta (as in most Sharks), in other Lacertilia, and Birds, there is only a 
small ethmo-palatine cartilage, early confluent with the antorbital portion of the nasal 
capsule ; it is a mere rudiment. 
Thus we get the correlated bony deposits developing almost irrelatively to the 
stunted axis of this arch; yet even they are ossifications of tracts of tissue that only 
needed time to have been formed into true hyaline cartilages. 
Therefore it is evident that these membrane bones are not to be confounded with 
such as are mere ossifications of a subcutaneous “ stroma,” homologous with the inner 
layer of a Ganoid scute. 
The palatines (Plate 42, fig. 2, pa.) form an open angle where they meet, embracing 
the ends of the vomers ; they are then arched and hollow over the inner narial passages, 
and they thicken greatly at their outer edge, which is emarginate. 
Behind, they form an open angle to embrace the fore ends of the pterygoids—then 
meso-pterygoid region, which does not become cut off, as in most Birds, and in Angais 
fragilis. 
They leave the base of the meso-ethmoidal cartilage exposed below, between the vomers 
and pterygoids ; these bones will also be seen in the sectional views (Plates 44 and 45). 
The other palatal element is detached from the palatine and clamps the transverse 
spur of the huge pterygoid ; this “transpalatine ” bar is fan-shaped, and its broad part 
is strongly tied to the under edge of the jugal and maxillary (Plate 42, fig. 3). 
With the maxillary, the thin palatal bones form a large oval fenestra on each side, 
a space very characteristic of the Lacertilian skull; another long, dagger-shaped 
fenestral space is seen on each side of the parasphenoid, with the pterygoid, outside. 
The pterygoids ( pg .) belong properly to the symplectic fore-growths of the sus¬ 
pensory part of the lower jaw; they reach from the tympanic cavities to almost the 
end of the vomers, and correspond to all but the broad fore end of the pterygo-palatine 
of Proteus, Menobranchus, and the larvae of the Perennibranchiate Urodeles. 
That primordial generalized bony plate breaks up in various ways, or in the low 
forms keeps in one piece pin most Urodeles the transverse process of the pterygoid 
reaches the jugum in the adult. 
The counterpart'bone in Birds nearly always segments off the front spike to fuse 
it with the palatine; and in the Passerines, the transpalatine is a solid piece of car¬ 
tilage, which ossifies by ectostosis, and then becomes ankylosed to the palatine. 
So that Nature “deals” these morphological “cards” in a great number of ways, 
and a vast amount of variation is obtained by this shifting, and as it were “ shuffling ” 
of things very simple in their nature, and similar hi their origin; these matters, 
well understood, expand our ideas as to what can be done in a high organism by 
metamorphosis, and greatly help the cause of the “ Evolutionist.” 
