832 THE CRUSTACEA. $ 280. 
§ 280. 
A large portion of the Crustacea have glandular appendages to the 
digestive canal. But it is only a few of these organs to which can be at- 
tributed the function of Salivary Glands. Two such of a lobular form, 
are found in the Cirripedia on the stomach, and pour their secretion intc 
the anterior part of this organ.” 
But with the Myriapoda, these organs are very distinct. There are 
two or more on each side of the oesophagus and stomach, and their rather 
long, excretory ducts open into the oral cavity.” With all the other 
Crustacea, these organs are wholly wanting.* 
The Liver, which exists sometimes as a glandular layer enveloping the 
digestive canal, and sometimes as a separate organ, is composed of green- 
ish, or of yellowish-brown tubes of variable size, the walls of which are 
formed by numerous granular cells, between which are interposed fat-vesi- 
cles. With most of the lower Crustacea, with the Siphonostoma, the 
Lophyropoda, the Phyllopoda, and Myriapoda, the liver is not isolated 
from the digestive tube, but the follicles of its glandular layer are some- 
what protuberant on the external surface of this tube, and open on its. in- 
ternal surface, euch probably by a separate orifice.® With Argulus, 
1 See Cuvier, Mém. loc. cit. p. 10, fig. 9, u. u., 
11. da, (Lepas) ; Burmeister, loc. cit. p. 42, Tab. 
IL. fig. 13, 14, c. (Coronula) ; Karsten, Nov. Act. 
Nat. Cur. XXI. Tab. XX. fig. 1, d. (Balanus). 
2 With Lithobius, and Scutigera, there are 
two compact salivary glands which extend from 
the head into the first segments of the body (L. 
Dufour, loc. cit. p. 838, 95, Pl. I. V.). T'revi- 
ranus (Verm. Schrift. IL. p. 25, Taf. V. fig. 4, q. q.) 
regarded them as a mass of fat. The botryoidal 
glands, which open by several excretory ducts into 
the oral cavity, have been observed by Gaede 
(Wiedemann’s zool. Mag. I. p. 107, Taf. I. fig. 7,i 
i.), by Mailer (Isis, 1829, Taf. II. fig. 5), and by Ku- 
torga (loc. cit. p. 4, Tab. I. fig. 4), in the anterior 
extremity of the body of Scolopendra. With 
Glomeris, there are only two short, slightly flex- 
uous glandular tubes situated in the lower portion 
of the head and opening into the mouth (Brandt, 
in Muller’s Arch. 1837, p. 323, Taf. XII. fig. 3). 
With other Myriapoda, these organs quite resemble 
those of the Insecta. Thus, with Geophilus, there 
are two flexuous tubes situated pretty far behind the 
nead, and from’which pass off two very long, small 
excretory ducts along the cesophagus to the 
mouth (Lreviranus, loc. cit. p. 37, Taf. VIL. tig. 
* [§ 280, note 2.] For the salivary glands of 
Julus see Leidy (A Flora and Fauna within Living 
Animals, p. 17, Pl. VII. fig. 21, a.b. In Smithson- 
ian Contributions to Knowledge, V. 1853). Beside 
- the long tubular glands mentioned by the authors 
above, he has described two others which are 
placed on each side of the cesophagus and are 
pyriform, conglomerate, and cellular in structure. 
Wright (Ann. Nat. Hist. 1848, p. 140) has also 
made observations on the glands of Geophilus 
which open into the head; he has shown them to 
be veneniferous, for a single excretory duct passes 
off from the anterior part of this gland and termi 
3). With Julus, the salivary organs are even 
longer and form, with the urinary canals, a very 
complicated net-work about.the stomach, and from 
which pass off, according to Treviranus (loc. cit. 
p. 44, Taf. VIII. fig. 6), three excretory ducts to 
the mouth. But Ramdohr (Abhandl. &c. p. 149, 
Taf. XY. fig. 1, g. g.) has figured only two simple 
salivary canals with Ju/us, and this number has 
been verified by Burmeister (Isis, 1834, p. 136). 
I have seen these two canals with Julus sabulosus 
anastomose in an arcuate manner at their posterior 
extremity.* 
3 For the intimate structure of the biliary tubes, 
see Schlemm, De hepate ac bile Crust., loc. cit. p. 
1d, Tab. IL. fig. 1-8 (Astacus), and Karsten, 
Nov, Act. Nat. Cur. XXI. p. 295, Tab. XVIII. 
-XX. (Oniscus, Astacus, and Balanus). 
4 An hepatic layer of this kind may be observed 
with the Penellina, Lernaeodea, Ergasilina (Vord- 
mann, loc, cit. Taf. I.—X.), and with Artemia (Joly, 
loc. cit. p. 239, Pl. VIII. fig. 4). The numerous 
caeca, which, according to Rathké (Nov. Act. Nat. 
Cur. XX. p. 122, Tab. V. fig. 15), belong to the 
entire digestive canal of Chondracanthus, are 
perhaps formed by an hepatie substance. With 
the Chilognatha, and Chilopoda, I have found the 
nates, on each side, in a canal of the jaw or mandi- 
ble, as in the Arachniodae. — Ep. 
t [§ 280, Dana (Report, &c., loc. cit. p. 13839) 
speaks of several small glands about the mouth, 
and communicating with it by ducts, with the Cali- 
goidea, and which are probably of a salivary 
nature. These organs in Argulus have been care~ 
fully examined by Leydig (Ueber Argulus, &c., loc. 
cit. p. 383, Taf. XIX. fig. 2, a.), and especially as 
to their relations to the spicula (see § 278, note 6) 
of these animals. Leydig thinks they may as 
well be regarded poisonous as salivary glands. See 
my note under § 278, note 7. — Ep. 
