388 
MR. NEWPORT ON THE NERVOUS SYSTEM 
third ganglion, [Plate XII. fig. 1. (3, g, g),] distribute from their base a small 
branch, which looks like a distinct nerve, while their main trunks, at a distance 
from the ganglion, divide into two branches, and are given to the second pair 
of legs. The cords between the third and fourth ganglia produce also a 
nerve that unites, in a manner similar to the preceding, with the first nerve 
from the fourth ganglion, [fig. 1. (4, i, «),] and forms a trunk which ramifies 
among the muscles of the fourth segment, and is destined for the second pair 
of wings. The second pair of nerves from the fourth ganglion [fig. 1. (4, k , /;),] 
are given to the third pair of legs. The nerves from the fifth ganglion [fig. 1. 
(5, l, Z)] belong also to the thorax, and are those which are given to the mus¬ 
cles of the hinder part of the thorax in the perfect insect. 
Nerves of the Abdomen .—All the nerves from the sixth to the terminal or 
eleventh ganglion, belong to this division, and, with the exception of those 
from the latter, are pretty nearly uniform both in number and distribution. 
Each ganglion produces one pair of small nerves, and one of large. The 
small ones are given to the fat and minute tracheae of the ventral surface. The 
large ones pass transversely across the segments, and divide each into two 
branches. One of these [Plate XIII. fig. 1. (q, q, q, q)~\ passes over the inner 
range of fibres and between the layers of abdominal muscles, and following 
the course of the trachea gives its branches to the dorsal muscles, and to the 
integuments of the back ; while the second, [fig. 1. (r, r, r, r),] passing also be¬ 
tween the layers of ventral muscles, distributes its branches to their inner sur¬ 
face, and to the integuments of the under surface of the body. The eleventh 
or terminal ganglion [Plate XII. fig. 1. (11)] produces five pairs of nerves, four 
of which are of considerable size. These are arched backwards, and three of 
them are given to the remaining segments of the body, while the others supply 
the colon, rectum, and rudiments of the organs of generation. 
Besides the nerves thus described, as constituting those of the head, thorax 
and abdomen, there are others which merit some attention, as they seem to 
form a distinct or superadded series. Lyonnet has accurately delineated them 
in his excellent Anatomy of the larva of the Cossus. There is a plexus of 
them lying transversely in every segment, attached by apparently a single 
filament, passing between the longitudinal cords to the posterior part of 
every ganglion, [Plate XII. and XIII. fig. 1. (e, h , o, o, o, o, o).] Some of the 
