37] THE NASAL ORGAN IN AMPHIBIA—HIGGINS 37 
Knorpelstab, der sich bis in die Mitte des Opticusfensters erstreckt und 
seinerseits wieder in zwei Theile gespalten sein kann. Eine dichte Zellan- 
hiufung verbindet die einzelnen Stiicke mit einander und mit dem Fort- 
satze des Quadratum, so dass die betreffenden Elemente wohl als eines 
Ursprungs aufgefasst werden kénnen.’’ The term palatal cartilage is a 
misnomer at least, for it is evident that the palatine bone, which is mem- 
brane in origin, could hardly be derived from this cartilage 
The capsule of the older larva, 90 mm. long, (Fig. 33) differs consider- 
ably from that just described; the greatest change taking place in the more 
anterior parts. The ossification of many of the covering bones, and the 
resorption of certain cartilage structures, as well as the chondrification of 
others, has resulted in a capsule very different from that of any other 
Amphibian. 
The preorbital and postorbital bands are much as before and need no 
further description, with the exception of the statement that they are 
more oblique, from medial and dorsal to lateral and ventral, than before. 
Through resorption, all connection between the preorbital band and the 
planum basale has been lost, so that a short caudal process from the planum 
on each side of the median line is a remnant of a trabecula, all intermediate 
parts having become ossified. The planum basale is shorter than before 
and the solum nasale or cornu trabeculae is now more posterior and in line 
with the caudal margin of the basale, which it unites to the lamina externa 
as in the early stage. The antero-lateral margin of the planum is more 
semicircularly excavate than before, and the tips of the trabeculae, extend- 
ing beyond the basale are more slender, the internasal space between them 
being wider and deeper. 
The planum verticale (fv), arising from the median line of the basale is 
wider than before, although not relatively as high. It is continued 
posteriorly into an elongate cylindrical process which extends backward 
to the level of the posterior margin of the basale, the dorsal root of the 
olfactory nerve lying lateral to it; while anteriorly it extends forward into 
a similar process reaching nearly to the tip of the snout. The alary proc- 
esses, flanking the median rostrum of the verticale, which were just 
beginning to chondrify in the earlier stage, have now grown forwards and 
outwards covering the more anterior parts of the nasal sac and uniting 
with two lateral processes yet to be described, each forms a partial cupola, 
incomplete ventrally which protects the anterior ends of the olfactory sac. 
There is a small foramen near the lower margin of this cupola, through 
which a branch of the profundus nerve leaves the capsule. 
The lateral wall of the capsule of this older stage is considerably 
different from that described above. The orbito-nasal foramen, the 
medial process of the lamina externa and their nerve relations are as before; 
but ventral to the foramen for the externus branch of the profundus, the 
