474 LANDACRE AND McLELLAN 
branchial X (figs. 1 and 2, G.V.X'). Its longest diameter, like 
all other members of the vagus complex except the jugular and 
branchial, is the dorso-ventral. It projects somewhat further 
caudad than the ventral lateralis but not so far as the dorsal 
lateralis. 
The position of this ganglion in Strong’s plot cannot be deter- 
mined with certainty. The portion of the X complex from which 
the visceral rami arise is represented as a mesial projection 
attached to the main ganglionic mass at the level of the ganglion 
B2. It is labelled ‘ramus visceralis 3’ but is described by Strong 
as containing ganglion cells. There seems no doubt that the 
ramus visceralis (3) of Strong’s plot represents the apex of our 
visceral ganglion, but whether the proximal part of our visceral 
ganglion is represented by B! or B? of Strong’s plot is uncertain. 
It is probably represented by B', since the rami branchiales seem, 
on his plot, to come from B?. The comparison on this basis har- 
monizes the two plots, since in the earlier stages represented in 
our plot the branchial nerves come from the branchial ganglion. 
The relations in the 10 mm. embryo plot are quite clear and bar- 
ring the reduction in the number of branchial nerves are quite 
’ typical. 
The visceral nerves arising from this ganglion emerge from 
its ventral apex. There are two chief divisions at this stage. 
The more ventral arises in conjunction with the ramus lateralis 
ventralis (L.X.V., figs. 1 and 2) and the other arises somewhat 
more proximally and pursues a course directly posterior. This 
last branch is undoubtedly the ramus intestinalis (figs. 1 and 2, 
V.X.). As to the composition of the first, the branch arising 
with the lateral line ramus, there is less certainty. It probably 
is not purely sensory, but contains a large motor ramus, (4) of 
Strong’s plot. But there are certainly visceral fibers in it also, 
probably supplying the fourth gill. 
