INTERNAL ANATOMY OF INSECTS. 13 
seven in the hive-bee and some Lepidoptera a ; eight in the 
grub of the stag-beetle b ; nine in the great Hydrophilns c ; 
ten in Dytiscus d ,• eleven in the grub of the great Hydro- 
philns */ twelve in the grub of Dytiscus and the caterpil- 
lars of Lepidoptera f ; thirteen in the larva of JEs/ma s ; 
and twenty-four in Scolopendra morsitans h . You must 
observe that, generally speaking, the number of ganglions 
is less in the imago than in the larva. With regard to 
the distribution of these knots to the different primary 
parts of the body, the following table will exhibit it, as 
far as I am acquainted with it, at one view. I omit those 
in which the ganglions are only in one of these parts. 
Head. Trunk. Abdomen. 
Acrida viridissima ....1 3 6' , 
Hydrophilns piceus . . . . 1 6 2 
Clubiona atrox 2 1 
Gryllotalpa vulgaris . . ...... 2 7 k 
Myrmeleon, Larva ....0 2 .8 1 
Eristalis tenax 3 2 m 
Apis mellifica 3 4 
Ephemera, Larva 3 7 
JEshna, Larva ...... 6 7 
3. I am next to say a few words upon the shape of the 
ganglions. Most commonly it approaches to a spherical 
figure, but in many instances, as I said before, they, as 
a Cuv. ubi supr. 348. b Ibid. 320—. c Ibid. 340—. 
d Ibid. 338— . ' Gaede ubi supr. 
{ Cuv. ubi supr. 323—. 327—. Mr. Bauer (Phil. Trans. 1824. t.'n. 
f. 1.) has figured only seven, excluding the brain, in that of the silk- 
worm, and Malpighi (De Bombyc. t. vi. /. 2.) ten, — Swammerdain 
(Bib/. Nat. t. xxviii./. 3.) however has twelve. 
* Ibid. 326. h Ibid. 352. ' Ibid. 343—. 
k Ibid. 345. • Ibid. 325— m Ibid. 351, 
