114 THE HELMINTHES. $ 109. 
tions, and which terminates in a short muscular rectum. The proper intes- 
tine is of a brown, greenish, or dirty yellow color, which is.due to its walls 
being formed of compact cells filled with colored granules. The loose and 
cellular walls, having very feeble peristaltic movements, are surrounded 
externally by a kind of dense peritoneum, and lined internally by a very 
fine epithelium.” In some species of Ascaris, the intestine is lengthened 
into a caecum at its junction with the esophagus. 
§ 109. 
There are observed, here and there, only traces of appendant organs of 
the digestive canal. | 
In many Trematodes, there are upon each side of the neck, two more or 
less developed cords or canals, of a cellular aspect, and of a pale yellow 
color by direct light. They pass towards the mouth, open perhaps into its 
cavity, and have a function, probably, like that of salivary organs. In 
many Nematodes, two or four caeca extend from the cephalic extremity 
along the cesophagus, and as they open distinctly into the oral cavity, it is, 
therefore, the more probable that they should be regarded as salivary 
organs.? The same signification should be given to the coecal appendage 
found in many species of Ascaris, which extends from the constriction of 
the cesophagus to the beginning of the intestine. ® 4 
Hepatic organs have been found nowhere but in the Nematodes; but it 
may be that the granular cells in the thick walls of the intestinal canal, 
take their place. 
5 This epithelium has sometimes special inequali- 
ties, which, with Ascaris osculata, and spiculige- 
ra, form a regular zig-zag series, resembling the 
valves of the intestinal mucous membrane of some 
vertebrates. With Ascaris aucta, they have the 
form of long, sharp villosities. 
6 This caecal appendage, accompanied usually 
with a constriction of the posterior end of the 
«esophagus, was first observed by Mehlis (Isis. 
1831, p. 91, Taf. IL. fig. 16,17, 18). It is found 
with many Ascaris, but its length is very variable. 
In Ascaris heterura, semiteres, and ensicaudata, 
it is very short, and protrudes scarcely beyond the 
cesophageal constriction ; while in Ascaris depres- 
$a, aucta, angulata, and mucronata, it reaches to 
the middle of the cesophagus, and in Ascaris spi- 
culigera, osculata, and the species described as 
Filaria piscium, it extends nearly to the cephalic 
extremity.* 
' These glandular-like organs are often very 
distinct in*the cercarian larvae of the Trematodes, 
and in many adults of Monostomum, and Disto- 
mum ; see Wiegmann’s Arch. 1843, IL. p. 322. 
2 Mehlis (Isis, 1831, p. 81, Taf. II. fig. 6) has 
observed with Strongylus armatus, an annular 
vessel surrounding the mouth, which communi- 
* [ § 108, note 6.] See, for the alimentary canal 
cates with it directly, and also with two cords 
accompanying the cesophagus. According to him, 
there is also a similar disposition with Strongylus 
hypostomus, and tetracanthus. 
Similar appendages, analogous to salivary or- 
gans, occur, according to Owen, in the new genus 
Gnathosoma, as four caeca surrounding the ceso- 
phagus, and opening into the mouth (Wieg- 
mann’s Arch. 1838, I. p. 134). With Cheiracan- _ 
thus, and Ancyracanthus, there are four similar 
organs, and Diesing is certainly in error in 
regarding them as analogous to the ambulacral 
vesicles of the Echinoderms (Ann. d. Wiener Mus. 
IL. Abth. 2, p. 224, 226, 228, Taf. XVII. fig. 8, 9, 
Taf. XVIIL. fig. 3). Iam disposed to regard as 
salivary organs, also, the two long caeca which 
pass from the mouth along the cesophagus of 
Strongylus striatus. 
3 I have discovered a similar oesophageal ap- 
pendage in a group of Ascaris known as Filaria 
piscium (Wiegmann’s Arch, 1838, I. p. 3809) ; 
such are, Ascaris mucronata, angulata, oscu- 
lata, spiculigera, aucta, acus, and labiata. It is 
remarkable that with the exception 0 the last two, 
all these have also a caecum upon the intestine. 
of Ascaris infecta, Leidy (A Flora and Fauna 
within living animals, Smithsonian Contrib. V. Art. 
2, p. 43, Pl. VI. fig. 1-7). He divides it into a 
strongly muscular gizzard, a cylindroid intestine 
lined with hexahedral epithelium, and a pyriform 
rectum. 
See also his description of that of Streptoso- 
mum, Thelastomum, &c. (Ibid. p. 49). In The- 
appendiculatum, there is this pecu- 
liarity, that the intestine commences by a broad, 
deeply sinuate, cordiform dilatation, which rapidly 
narrows to a short, cylindroid portion, and then 
sends off a jong, cap , gourd-form receptacle, 
or diverticulum, and afterwards proceeds back- 
wards to the rectum, and in its course, in the vi- 
cinity of the generative aperture, performs a single 
short convolution, — Ep. 
