Span JULIA B. PLATT. 
A branch supplying the short dorsal row of sense-organs may 
be distinguished in the nerve-plexus which here underlies the 
skin. The ramus buccalis has been mentioned. A _ small 
branch, the ramus oticus, connects the solitary supra-branchial 
sense-organ of the hyomandibular cleft directly with the facial 
ganglion. . 
The ventral branches of the facial, glossopharyngeal, and 
first vagus ganglia closely resemble one another. Hach ganglion 
rests upon the dorsal wali of the corresponding branchial cleft, 
and sends a large branch downwards, from the proximal end 
of which another branch runs backwards and outwards into 
that branchial arch on the anterior wall of which the main 
nerve lies. A third and smaller branch extends from the 
ganglion inwards and forwards on the dorsal wall of the 
branchial cavity. In the facial group this anterior branch, 
the ramus palatinus, is already fairly developed, but the fibres 
running forwards from the glossopharyngeal and vagus ganglia 
can hardly as yet be called nerves. They resemble a bush of 
tiny fibres, leaving the ganglion in a bundle, but almost 
immediately scattered and lost on the adjacent pharyngeal 
wall. 
The vertical branch of the facialis, the ramus hyomandibu- 
laris, begins like the following branchial nerves close to the 
posterior wall of the branchial pocket, but almost immediately 
crosses the dorsal corner of the pocket, and comes in contact 
with the skin at the point where the endoderm of the hyoman- 
dibular pocket last touches the ectoderm. Here for a short 
distance the nerve is bounded within by the endoderm, without 
by the ectoderm; but as the branchial pocket recedes from 
the surface of the embryo the nerve clings to the ectoderm, 
and divides into its two sensory branches, which closely underlie 
the corresponding sensory ridges. 
The vertical branchial nerves of the glossopharyngeus and 
vagus begin at relatively the same point as the hyomandibularis, 
but continue as they begin close to the endodermic wall of the 
gill cleft, which they follow downwards. Then, turning 
inwards with the gill cleft, the distal part of the nerve occupies 
