386 
MR. NEWPORT ON THE NERVOUS SYSTEM 
From the front, or most convex surface of this ganglion, originates a small 
branch that distributes filaments in the direction of the superior lip ; while a 
large nerve is produced from the posterior surface, [fig. 2. (e, e),] which passes 
backwards beneath the cerebral lobes, along the middle of the oesophagus, 
covered by the dorsal vessel. On arriving at the stomach, it divides into three 
branches, [PI. XII. fig. 2. (e, e ); PI. XIII. fig. 2,] which are distributed chiefly 
to that organ. Throughout the whole of its course, from the ganglion to this 
division into branches, it distributes filaments to the dorsal vessel and to the 
oesophagus. I have not yet succeeded in tracing it in this insect beyond the 
anterior part of the stomach, but in the Gryllus viridissimus, Linn., I was 
once enabled to follow its central division along the whole of the stomach, and 
part of the small intestine, from which, with a little care, it was readily de- 
tached. Its length from the ganglion to the trifid division in the Sphinx, is 
much increased during the changes of the insect, and corresponds precisely 
with the elongation that takes place in the oesophagus. The form of the gan- 
glion undergoes no alteration. From the analogy that exists in the distribu- 
tion of this nerve to that of the eighth pair in the vertebrated animals, it is 
probable that its functions are of a somewhat similar nature, — that in reality 
it is the par vagum, or pneumogastric nerve of insects. In fact, this is the 
pretty generally received opinion respecting it, and is clearly that of Straus 
Durckheim, who describes it in his Anatomy of the Melolontha vulgaris. It 
must be confessed, however, that there are objections to such an opinion, since 
it is not yet proved to distribute any filaments to the respiratory organs, 
although it can hardly be doubted that such distribution does really exist, 
when we remember the abundance of tracheal vessels which ramify upon the 
stomach, and with which its filaments must necessarily come in contact. The 
other nerves from the cerebral lobes arise nearer the lateral surfaces. The 
first of these are destined for the future antennae, and proceed from the front, 
near the origin of the cords, [PI. XII. and XIII. fig. 2. (d).] At the last period 
of the larva state they are of considerable size and length, and lie packed in 
sigmoid folds on each side the head, within the cranium. The next are the 
optic nerves. These come from the upper part of each lobe, [PI. XII. and XIII. 
tig. 2. (b),] and in the larva are scarcely more than slender cords directed dia- 
gonally outwards to the six minute eyes. In addition to these nerves from the 
