246 
MR. NEWPORT ON THE NERVOUS AND CIRCULATORY SYSTEMS 
lobe at its junction with the descending crus, a thick trunk of nervous matter (e) is 
extended forwards and transversely across the front of the head, above the palate and 
mouth, and uniting with its fellow from the opposite side, forms in the middle line a 
small triangular ganglion (/'). These nervous trunks are the analogues of the recur- 
rent nerves in insects, from which the visceral nerves (Zr) take their origin. In these 
Myriapoda the recurrent nerves are more extensively developed than in the other 
classes, and they seem to decrease in importance as in size, in proportion as the other 
parts of the nervous system are developed. The small triangular ganglion formed by 
them above the palate, sends backwards in the middle line a short thick nerve, which 
terminates immediately before the brain in a more indistinct ganglion that gives off 
three branches. The middle one of these is much smaller than the lateral, and passes 
backwards beneath the brain along the pharynx and oesophagus in a small triangular 
space between the lobes, covered by the median vessel from the heart, that passes 
between it and the brain and gives vessels to that organ. This median nerve from 
the recurrent ganglion constitutes the trunk of the proper vagus nerve (/) ; while the 
others from the same ganglion, each of which is more than twice as large as the 
vagus, after giving off some minute filaments to the pharynx and oesophagus, descend 
to the sides of the pharynx and pass backward between it and the crura cerebri (g) 
on each side (h), to unite at a short distance behind the brain with a series of large 
visceral ganglia (m) collected together, and constituting the analogues of the anterior 
lateral ganglia of insects. This series of ganglia, as in insects, is connected to the 
brain by two small communicating nerves ( n ), extended backwards from the posterior 
surface of the lobes, near where they are joined to the optic ganglia. These lateral, 
visceral ganglia in lulus, are of most extraordinary size, being nearly half as large as 
the brain itself. There are four on each side of the oesophagus, closely connected in 
one series, extended along the oesophagus as far as the middle of the first or pro-tho- 
racic segment, giving off branches of nerves to the immense salivary glands, to the 
oesophagus itself, and to the surrounding structures. They exhibit the appearance of 
masses of gray nervous matter inclosed in a distinct theca. The last of the series 
extends a little further backwards than the aortic arches given off from the anterior 
chamber of the heart. They seem to be the anterior of an extensive series of visceral 
ganglia, distributed in great part to the salivary glands. They communicate with the 
vagus by means of a nerve that passes directly from the last of these ganglia, on each 
side, to a large ganglion formed on the vagus (o) at some distance from the brain. 
The vagus nerve, after passing beneath the brain, forms a minute ganglion (?) imme- 
diately behind it, which is also connected to the lateral ganglia by a very minute 
hranch on either side. It then passes along the oesophagus and forms the second 
larger, rounded ganglion, first mentioned as connected to the last of the lateral 
ganglia. After this it continues its course backwards half way along the oesophagus, 
and then divides into two branches, which are given, as in insects, to the posterior 
part of this organ, and to the cardiac extremity of the stomach. 
