Comparative anatomy / by C.Th. v. Siebold and H. Stannius ; translated from the German, and edited with notes and additions recording the recent progress of the science by Waldo I. Burnett.

  • Karl Theodor Ernst von Siebold
Date:
1854
Catalogue details

Licence: Public Domain Mark

Credit: Comparative anatomy / by C.Th. v. Siebold and H. Stannius ; translated from the German, and edited with notes and additions recording the recent progress of the science by Waldo I. Burnett. Source: Wellcome Collection.

Provider: This material has been provided by The University of Glasgow Library. The original may be consulted at The University of Glasgow Library.

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    With the Hirudinei, the intestinal canal varies very much, especially as to the number and volume of its appended coeca/2' Its very narrow anal opening is upon the back directly above the pedal sucker.® With Nepke- lis, the canal is simple and gradually enlarges from before backwards, but has no coeca. With Branchiobdella, it is deeply constricted in several places.® With Pontobdella, it is simple with its two anterior thirds, but there is a caecum on each side of its remaining portion.® This last is also true of its posterior third with Haemopis, Clepsine, and Sanguisuga.{6) With this last genus, the other portions of the canal are divided by ten or eleven constrictions into as many parts which send oil’ on each side short caeca; (,) while that of Clepsine has on each side five or six coeca, all of which may be rami- fied. There is a kind of valve directly behind the last two caeca, and so, the part of the intestinal canal in front of this may be regarded as a stom- ach and a small intestine, while the remaining portion behind it, represents the rectum.*' With the Abranchiati, the intestinal canal is short, and its oesophagus' which is usually narrow passes into a muscular pharynx, which leads into a stomachal dilatation. Upon these parts follow the remaining portions of the intestine which are separated from each other by the transverse septa of the body and often resemble the stomach. With a few species only, the stomach is remarkable for its thick, muscular walls.® With some of the Capitibranchiati, the digestive canal arises directly behind the oesophagus and has bulging portions like those of the colon/® assuming, posteriorly, sometimes a spiral form.(11) With others, the oesoph- agus is continuous directly into the intestinal canal, which, free and un- attached by diaphragmatic septa, makes many turns in the cavity of the body, and by constrictions is divided into a stomach, small intestine, and rectum/12' With many Dorsibranchiati, the intestine follows directly upon the oesophagus, and is either straight and divided by constrictions/18' or assumes a spiral form114' or is without constrictions and irregularly tortuous/® With others, the portion of intestinal canal between the pharynx and in- forms with the buccal orifice, a cavity distinct from that of the abdomen, and its anus has a kind of sphincter. But this is certainly an erroneous view of the organization of these worms : the contents of the cavity are sufficient alone to confute it. 2 Moquin-Tandon, loc. cit. PI. I.-IV. 3 With Piscicola, exceptionally, the anus is up- on the ventral surface of the last segment of the body •, see Leo, in Muller'1 s Arch. 1835, p. 420. 4 Uenle, Muller's Arch. 1835, Taf. XIV. tig. 1. 5 Wagner, Isis, 1834, p. 130, Taf. I. fig. 1, 2. G Brandt and Ratzeburg, Wed. Zool. II. p. 246, Taf. XXIX. B. fig. 12. 7 Ibid.-Taf XXIX. A. fig. 19, 20, 55. 8 With Clepsine mar ginata, this rectum has coecal appendages also *, see F. Muller, in Wieg- tnann's Arch. 1844, I. p. 371, Taf. X. fig. 14.* 9 With Lumbricus, the stomach is very muscu- lar ; see Morren, loc. cit. Tab. XI.-XIV. This is also true of Nais proboscidea, but not with Lum- briculus, and Enchitraeus. * (§ 154, note 8.] For many special details illustrating as well the histology as the anatomy of the intestinal caDai of the Hirudinei {Piscicola, 10 Terebella, and Sabella; see Grube, Zur Anat. d. Kiemenwiirmer, p. 20, 27, Taf. II. fig. 12, and Milne Edwards, Ann. d. Sc. Nat. X. 1838, PI. X. XI. 11 Sabella ,* see Cams and Otto, Erlauterungs- taf. lift. IV. Taf. III. fig. 4, 6, and Wagner, Icon, zoot. Tab. XXVII. fig. 21. 12 Amphitrite, and Sip/innostojnum. With the first, the stomach is long, spiral, and divided into an ascending and a descending portion ■, see Rath- k<[, Danzig. Schrift. loc. cit. p. 64, 86, Taf. V. VI. 13 Amphinome, Arenico/a, Eunice, and Neph- tys ; see Stannius, Isis, 1831, Taf. VI. fig. 10 j Milne Edwards, Ann. d. Sc. Nat. X. 1838, PI. XII. XIII. ; Grube, Zur Anat. d. Kiemenw ii rmer, Taf. I. 14 According to Grube (Ibid. p. 34), the intes- tine of Cirratulus is spiral like that of Sabella. 15 Ammotrypane (according to Grube, see Rathfce, Nov. Act. Acad. Nat. Cur. XX. p. 197, Tab. X. fig. 13). Clepsine, Nephelis), see Ley dig, loc. cit. p. 110, Taf. VIII. IX. fig. 24-37.— Ed.