INTERNAL ANATOMY OF INSECTS. 15 
lineated, form no unpleasing picture 3 . In the caterpillar 
of the goat-moth the accurate Lyonet counted forty- 
Jive pairs of them, and ttvo single ones, making in all 
ninety ~pWQ nerves ; whereas in the human body anatomists 
count only seventy-eight b . From the brain issue several 
pairs, which go to the eyes, antennae, palpi, and other 
parts of the mouth : sometimes those that render to the 
mandibles issue from the first ganglion, as in the larva 
of Dytiscus marginalis, the stag-beetle, &c. c ; those both 
of mandibles and palpi in the great Hydrophilus d ; and 
in Blatta some which act also upon the antennae e . 
The optic are usually the most conspicuous and re- 
markable of the nerves. In some insects with large eyes, 
as many Newoptcra, Hymenoptera, and Diptera, their 
size is considerable ; in the hive-bee they pi'esent the ap- 
pearance of a pair of kidney-shaped lobes, larger than 
the brain f ; in the dragon-flies, whose brain consists of 
two very minute lobes, these nerves dilate into two large 
plates of a similar shape, which line all the inner surface 
of the eyes s ; in the stag-beetle they are pear-shaped, and 
terminate in a bulb, from which issue an infinity of mi- 
nute nerves h ; it is probable that this takes place in all 
cases, and that a separate nerve renders to every separate 
lens in a compound eye i ; the optic nerve in Dytiscus and 
Carabus is pyramidal, with the base of the pyramid at the 
eye and the summit at the brain k ; in Eristalis tenax it 
a Lyonet ubi supr. t. x.f. 5. 6. b Ibid. 192. 
c Cuv. ubi supr. 323. 335. 
d Ibid. ii. 339. « Ibid. 342. 
f Swamm. Bibl. Nat. t. xxii.f. 6. m.m. 
b Cuv. ubi supr. 350. h Ibid. 335. 
1 Vol. III. p. 495—. Lyonet. Anat. 581. 
k Cuv. ubi supr. 337. 
