ORIGIN OF JAW APPARATUS 385 
issue direct from the medulla in line with the axis of the nasal 
trunk, still another group of root bundles arise laterad of the 
root and curve mesad to enter the root of the nasalis. The 
nasalis is not a branch of any of the other roots, but a distinct 
and important nerve certainly equal in morphological value to 
the ophthalmic. Its position ventrad and sometimes laterad 
of the ophthalmic is due to the crowding of the parts of the tri- 
geminal complex into such narrow quarters that the fiber bundles 
leaving both the mesial and lateral borders of the medullary 
projection are both crowded ventrad on both edges, and curved 
inward below the medullary lobe. 
These root bundles unite into a cylindrical trunk which bends 
at once mesad or toward the brain running cephalad along the 
ventral border of the brain, nasal capsule, and nasal tube. It 
gives off small twigs to the fat-body inclosing it, then a large 
anastomosis to the ophthalmic near where the optic nerve passes 
outward between the two. The optic nerve passes dorsad of 
the nasalis, but ventrad of the ophthalmic, and the nasalis and 
ophthalmic exchange fibers at the cephalic end of the ganglion, 
and both give off a small number of fibers to the optic nerve 
and its fat-body where it passes between them. It thus reaches 
the nasal territory mesad of the ophthalmic and thus lies mesad 
of the ophthalmic for the larger part of its course. The terminal 
branches of the nasal division of the nerve in the anterior snout 
region are mainly close to and upon the nasal tube. The pala- 
tine division of the nerve ends in a brush of terminal branches 
which supply the mucosa of the roof of the mouth, the median 
tooth and from this region forward anastomose with the nerve 
veil and network of the snout. 
A bird’s-eye view of the nasalis nerve may be given as follows: 
It is the mesial root and thus the most anterior nerve of the 
jaw complex. It anastomoses with the ophthalmic nerve at 
its root also where the optic nerve passes between them, both 
giving off fibers which join the optic nerve trunk. It sends 
branches: 1) to the fat-body covering the V root; 2) to the optic 
nerve and fat-body; 3) to the posterior end of the nasal capsule; 
4) to the lateral fat-body of the nasal capsule; 5) to the ventral 
