ORIGIN OF JAW APPARATUS 387 
The roots of the ophthalmic nerve leave the brain, as shown 
in figures 31, 32, laterad and dorsad of the mesial bundles of 
the nasalis. They form the large nerve trunk which holds the 
mesial position among the nerves Jeaving the tip of the medulla 
seen from above, before the roots are dissected out. It soon 
anastomoses with both the nasalis and the maxillary trunks 
and runs forward diverging slightly laterad from the sagittal 
plane. Near the level of the posterior end of the nasal capsule 
it gives off a superficial branch, sometimes two branches, which 
rises to the surface of the head just in front of the eye and enters 
the subdermal lymph space and joins the complex of nerves 
which ramify throughout the subdermal lymph space, in the 
skin and over the muscles forming the floor of the lymph space. 
Some of these ventral branches pass down between and also 
through the muscles to join the coarse nerve net of the inter- 
spaces and the loose connective tissue holding the muscle of 
the mouth in place. Similar branches rise from the deeper 
branches of the ophthalmic to join the complex and nerve net 
in the subdermal space (figs. 34 and 35 B). On reaching terminal 
territory the superficial branch breaks up into small nerves 
which join the jaw plexus which covers the snout region hke 
a fine-meshed veil (fig. 34). 
The main trunk of the ophthalmic runs forward and branches 
continuously to serve the muscles and other structures it passes, 
and the branches to the skin and tentacles terminate in brushes 
of fine fibers (fig. 835A). A large commissure of fibers passes 
between the ophthalmic and mandibular nerves at A, figure 
35. Altogether it is a remarkable bundle of fibers. 
The maxillary nerve roots form a large nerve leaving the 
dorsal lateral edge of the tip of the medulla as seen from above, 
and its roots are drawn together from a wide territory in the 
medulla (figs. 31 and 32). It is closely bound up with the man- 
dibular nerve and the anastomoses between the two near their 
origin from the medulla are extraordinarily extensive and com- 
plex, as shown in figure 33. There is great variation in the 
interchange of fiber bundles. I have selected the drawing shown 
in figure 33 as on the whole typical of the relation of these 
