CocuHiLL, fifth Nerve in Amphibia. 53 
V of Rana is performed in Amblystoma by the ophthalmicus 
profundus. 
In the light of these facts it becomes impossible to homol- 
ogize the ventral terminal branch of the opkthalmicus profundus 
in Amblystoma with the ramus communicans cum N. palatino 
in Rana. The former nerve is the equivalent of two nerves in 
Rana, the ramus communicans cum N. palatino of the ophthal- 
micus and that of the maxillaris. 
It isa noteworthy fact, also, that in Rana, according to 
Gaupp, the maxillaris nerve, in union with fibers from the oph- 
thalmic, innervates the muscle levator bulbi. In Amblystoma 
this muscle is innervated wholly by the ophthalmic. This is 
not only another case where the functions of the ophthalmicus 
profundus in Amblystoma are carried over to the maxillaris in 
Rana, but it shows that in Rana there is an intimate relation 
between the maxillaris and ophthalmic nerves, a relation which 
exists between the general cutaneous as well as between the 
motor components of the nerves as shown by the anastomoses 
between the terminal sensory twigs of the two nerves described 
by Gaupp. . 
An unqualified homology can not be established between 
the two species with reference to the other terminal branches 
of the ophthalmicus profundus. The lateralis narium of Rana 
is certainly not homologous with the lateral terminal branch of 
the nerve in Amblystoma, for the latter nerve innervates a re- 
gion belonging, at least in the greater part, to the maxillaris in 
Rana. Exact homologies in this region can be established only 
by far more extensive comparative and perhaps embryological 
data than have yet been compiled. 
The nerve which has usually been called the maxillaris in 
Urodela is of special interest in this connection. The discovery 
of a lateral line component in this nerve forced it out of com- 
plete homology with the maxillaris of Anura, but some anato- 
mists have called its general cutaneous component the maxil- 
laris. A comparison of this nerve with Strong’s lateral ‘‘acces- 
sory ramus’ of the trigeminus as to origin and distribution is 
quite conclusive. 
