GANGLIA OF RANA 471 
sometimes with lateralis IX. The ventral border of the ganglion 
diminishes in size and finally gives rise to a lateral line nerve which 
passes out with a visceral nerve of the X. 
The mesial border of the ganglion is more or less closely fused 
with the lateral surface of visceral X but can always be distin- 
guished from it by the larger size of its cells and by the fact that 
the cells are always heavily pigmented. The position of this 
ganglion in Strong’s plot is difficult to determine. Our series is 
not complete from 10 mm. to the 35 mm. embryo. The ganglion 
seems to shift its position proximally and join the dorsal lateralis 
ganglion, although not completely, since there are lateralis cells 
distributed along the dorsal surface of the visceral ganglion in the 
35mm. stage. It must be identified for the present, provisionally, 
in part, with the ganglion A of Strong and in part with the general 
position of his ganglion B! and B?, to which he does not attribute 
lateralis cells. The ganglion is not distinct in either Ambly- 
stoma or Amphiuma, although Norris (’08) shows in Amphiuma 
a rather sharp division between the portion of the ganglion from 
which his ramus medialis et dorsalis and that from which his 
ramus lateralis ventralis arises. The former probably corre- 
sponds to the dorsal lateralis ganglion of our plot and the latter 
to the ventral lateralis. One nerve arises from the ganglion. It 
springs from the extreme ventral end of the ganglion and corre- 
sponds to the ramus lateralis (5) of Strong’s plot. It also corre- 
sponds to the ramus inferior (Zi.) of Amblystoma (Coghill ’02) 
and to the ramus lateralis ventralis (Lat. V.) of Amphiuma 
(Norris ’08). 
In the embryo frog, as well as in Amblystoma and Amphiuma, 
this nerve passes out of the ganglion in conjunction with visceral 
fibers. This is not so evident in Strong’s plot, although his 
Ramus visceralis does come out of the ganglionic complex at the 
same point but the two trunks are separated up to the ganglionic 
mass. The conditions in our embryos are quite similar to the 
plots of Coghill and Norris, where the lateralis and the visceralis 
trunks pursue a similar course for some distance; at least one of 
the visceral rami is closely associated with the lateralis ventralis. 
The root of the ventral lateralis X passes dorsally to enter the 
brain with the roots of the dorsal lateralis X (figs. 1 and 2). 
