No.3.] MUSCLES AND NERVES IN AMIA CALVA. 689 
As the two roots approach the foramen they pass through 
what is apparently a ganglionic enlargement (gv), and there is 
always here, or between the two roots proximal to the enlarge- 
ment, an interchange, perhaps mechanical, of fibres, for one or 
more small nerve bundles were always broken in attempting to 
separate the roots. This apparent interchange of fibres, and a 
mass of ganglion cells on the root of the vagus, were also found 
at this point in larvae (No. 3, pp. 517 and 518), the ganglion 
cells being always confined to the root of the vagus, none of 
them appearing on the root of the lateral nerve. 
Beyond this intracranial ganglion, which lies inside the 
cranium, the nervus vagus separates immediately into its four 
main portions, or into three portions, the posterior of which 
soon separates into the two posterior main branches of the 
nerve. On each of these branches of the root, after they issue 
from the cranium, a well-marked ganglion is found, that on the 
first branch lying close to the side of the skull, the second close 
to the first, and the third and fourth at some little distance 
from the other two. From the intracranial ganglion the first 
branch of the nervus (stv) has its apparent origin, and runs 
outward and backward through the vagus foramen above the 
four main roots of the nerve. Immediately beyond the gang- 
lion, and ventral to the first branch of the nerve, the nervus 
lineae lateralis, now well rounded, runs backward across the 
upper surface of the four main vagus roots, median to their 
ganglia. On it, in the adult, there is no such ganglionic 
enlargement as was found in larvae, but a slight difference 
in the color of the nerve indicates undoubtedly its presence 
immediately beyond the intracranial ganglion of the main 
root. From the proximal portion of this discoloration, im- 
mediately outside the vagus foramen, or even still inside the 
cranium, the first branch of the lateral nerve (#//.s¢o) is given 
off, and joins at once the first branch of the main vagus 
root, with which it is intimately connected, but apparently 
without any interchange of fibres whatever. The two nerves 
issue from the vagus foramen together, turn upward and out- 
ward along the side of the skull, pass across the posterior angle 
of the intercalar median to the posterior process of that bone, 
