28 F. L. LANDACRE 
an ganglion. Apparently the ophthalmicus profundus has sup- 
planted largely the r. oph. sup. V in Amphibia. In higher 
forms the ophthalmic nerve seems to come from the Gasserian 
ganglion, in which case the r. oph. sup. V. has supplanted the 
r. oph. profundus. 
6. RAMUS MAXILLARIS V 
The ramus maxillaris V (figs. 1 and 4, R.Mz.V) arises from 
the ventral end of the Gasserian ganglion and pursues a course 
directly ventral to the position of the third lateral line organ 
innervated by the r. bucecalis VII, where it gives off a number 
of twigs to the ectoderm. From this point it turns slightly 
cephalad and before reaching its most distal point of distribu- 
tion gives off several small twigs (fig. 1, S./—4), all of which run 
to the ectoderm. The extreme end of this nerve breaks up into 
a number of twigs which could not in some cases be traced to 
the ectoderm and present the appearance of the tip of a growing 
nerve. 
The r. maxillaris is accompanied throughout its whole course 
by the r. buccalis which lies more lateral in position, but the 
two nerves are quite separate except at the level of the third 
lateral line primordium mentioned above where there are two 
fibrous connections between the two nerves (not shown in fig. 1) 
in which the fibers seem to pass from the r. maxillaris to the r. 
bucealis. The R. Mx. V. seems to be purely general somatic 
sensory. It has no connection at any point with the ganglion 
or nerves of visceral VII. There is a possibility that lateral 
line fibers enter it through the two anastomoses mentioned 
above, in which case it would contain a few lateral line or special 
somatic fibers. The appearance of the anastomoses do not 
favor this view and there are no lateral line primordia on the 
course of the r. maxillaris beyond the anastomoses. There is, 
further, an anastomosis (fig. 1, R.Com.) between the r. mandib- 
ularis V and the r. maxillaris V which will be described under 
the r. mandibularis V. 
