430 THE INSECTA. $ 339. 
whether one of the pairs of these glands with these Hemiptera, may not be 
@ poison apparatus. 
The Insecta have no distinct Hepatic Organs, but the function of a Liver 
is performed by the walls of the stomach, the internal tunic of which is 
composed of closely-aggregated hepatic cells. With many species whose 
stomach has caecal appendages, the walls of these last have a similar hepatic 
structure, and must secrete, therefore, a bile-like fluid.“ 
With some Insecta, the ileum has glandular appendages, whose product 
is perhaps analogous to a pancreatic fluid. The two or four rows of fol- 
licles which, as before mentioned, are situated on the ileum of the Penta- 
tomidae and some Coreidae, would, in the same manner, be regarded as a 
Pancreas. The same remark applies to the ramified appendages, which, 
with Gryllotalpa, open into the stomach below the two caeca, as well, also, as 
to the two or three follicles which, with Pyrrhocoris, are inserted, laterally, 
on the posterior part of the ileum. 
There is found, with all Insecta, a Corpus adiposum, — a tissue, composed 
of adipose cells, which is intimately connected with the functions of digestion 
and assimilation. This body is especially developed towards the end of 
the larval state, and it disappears, for the most part, during the pupa 
period, so that only a few traces of it are found with Insecta in their per- 
fect state. It is usually of a white, or a dirty-yellow color, but is also 
observed of a green. red, or orange hue. In the larvae, the fat ceils gen- 
erally form pretty large, lamelliform lobes, sometimes ramified or reticu- 
lated, sometimes plicated, spread through the abdominal cavity in all the 
intervals of the viscera. These lobes are always traversed and retained 
in place by numerous trachean branches. With the perfect Insecta, the 
remains of this body are not usually found except in the posterior portion 
of the abdominal cavity, where they consist of fat-cells loosely scattered, 
and not retained by the tracheae.™ 
18 For these biliary organs, see J. Miiller, De 
sur les Hémiptéres, p. 44, Pl. II. fig. 19, 21 (Pyr- 
Gland. struct. p. 67. The Malpighian vessels 
rhocoris).t 
which were formerly regarded as biliary tubes, 
will be treated of in future (§ 346).* 
19 See L. Dufour, Recherch. sur les Orthopt. p. 
332, Pl. IL. fig. 19 (Gryllotalpa), and Recherch. 
* [ § 339, note 18.] The liver of the Insecta, as 
well as that of the Invertebrata generally, has been 
investigated by Will (Miiller’s Arch. 1848, p. 502) 
who has lied the same chemical mode of in- 
quiry, as that of Brugnatelli and Wurzer upon 
the Malpighian vessels showing their urinary char- 
acter (see infra § 345, note 2). With the Insecta, 
he regards as hepatic the caecal and other glandu- 
lar appendages which, when present, lie upon the 
so-called Ventriculus, thus confirming the suppo- 
sition expressed in the foregoing note. For the in- 
timate microscopic structure of the liver of the In- 
secta, see Leidy, Amer. Jour. Med. Sc. XV. 1848, 
p. 1.— Ep. : 
+ [§ 339, note 19.) For the hepatic organs of 
Belostoma, see Leidy, loc. cit. p. 63, Pl. X. fig. 
4,i, They consist of four long very tortuous tubes 
20 See L. Dufour, Recherch. sur les Carabiq., in 
the Ann. d. Sc. Nat. VIII. 1826, p. 29; Recherch. 
sur les Hémipt. p. 141, and Recherch. sur les 
Orthopt. p. 291, 385, 562. ! 
closely applied to the intestinum tenue ; they join 
the intestine at the junction of the duodenum and 
ileum. — Ep. 
¢ [ § 339, note 20.] See, upon the Corpus adi- 
posum, Mayer (Ueber die Entwickelung. des Fet- 
tkérpers, &c. bei den Lepidopteren, in Siebold 
and Kélliker’s Zeitsch. I. p. 175) who has traced 
its development. 
These adipose bodies are formed from a great 
number of separate, flattened, usually many- 
pointed lobes. These lobes consist of pouches with 
. structureless walls, and filled with fat-globules. 
Each pouch is originally a simple cell with a large 
nucleus attached to its wall. In this cell are 
formed daughter-cells, which, when filled with fat, 
burst, and thereby the mother-cell becomes the fate 
containing sac. — Ep. 
