THE NASAL REGION IN EUTAENIA. 393 
pletely. The septomaxillary undergoes another change in form at 
the hinder half of the Organ of Jacobson it gradually loses the pro- 
longation on the outer and under surface of the Organ, which is there 
replaced by the vomer. It also rises and becomes more closely applied 
to the nasal wall. On the other hand, the cupped crest of the vomer 
becomes prolonged outward under the septomaxillary and parallel 
withit. ‘This portion of the vomer is much fenestrated to allow a 
passage to the Organ of Jacobson for the olfactory nerve bundles. 
Below, the basal portion reaches outward, and finally unites with the 
superior prolongation on the outer surface of the Organ. 
The vomer thus surrounds and envelopes the posterior, as the septo- 
maxillary does the anterior, termination of the Organ of Jacobson, 
behind which it divides into two portions, the inferior quickly dis- 
appearing, the superior losing its horizontal process rises, and with 
its fellow of the opposite side forms a capsule for the lower half of 
the nasal septum, now oval in section. Approaching the choana of 
its side, it descends again to apply itself to its inner wall, and 
terminates by sending a plate outward over the choanal roof to unite 
with the palatine bone. 
As before stated, the wings of the nasal septum pass out over the 
nasal cavities down their sides to connect with the turbinal earti- 
lages. The latter are provided in their front half with a concavity 
on the outer face of each, to which the Nasal Gland of Miiller accom- 
modates itself. This concavity deepens as the cartilage is followed 
backward, the edges approximating and forming ultimately behind a 
closed tube, containing a separate portion of the gland. (Fig. 4, Jfy’). 
This tube ends blindly with the turbinal ingrowth. 
In front a plate of cartilage, continuous with the turbinal, passes 
around the nasal opening, and is connected with the transverse pre- 
nasal wall. (Figs. 6, 7, ne, ne’.) Below, the turbinal is connected 
with the cartilage of the pedicle of the Organ of Jacobson by a 
narrow transverse plate passing under the septomaxillary. This 
transversely directed plate of cartilage is continued backward into 
two pieces, which in a transverse section containing the opening of 
the Organ of Jacobson are arranged, one immediately under the 
outer half of the latter, the other some distance laterally. (Figs. 3, 
4, Ic’, lc’.) These are the lachrymal cartilages, and are described 
below in connection with the lachrymal duct. 
28 
