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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    CHAPTER II. MUSCULAR SYSTEM AND ORGANS OF LOCOMOTION. §29. The movements of Polyps are performed, partly by contractions of the sides of their body, in which are found no muscular fibres, and partly by a true muscular tissue. The fibres of this tissue have not regular trans- verse striae, although during their contractions there are sometimes, though rarely, seen irregular transverse bands.<n §30. In those Polyps having a true muscular system, this tissue is composed of interlaced fibres, forming a layer beneath the skin. A coarse net-work of this kind is seen in the arms of Hydra, although in the foot and rest of the body there is scarce anything comparable to muscular fibres.11’ Under the skin of Synhydra^ and in the arms of Elcutheria&) this muscular system is much more apparent. A similar layer, very distinct, is observed in Acti- nia, which, in their mantle, is composed of both longitudinal and circular fibres, the contraction of which draws the tentacles together, and this, com- bined with that of the radiating fibres of the foot, gives rise to the various forms of these animals.® The Bryozoa have the muscular system more apparent; in the cavity of their body completely isolated fasciculi are seen, composed of parallel fibres, serving especially for the withdrawal of these animals into their cells. These fasciculi arise from the internal surface of the body, and are inserted partly into the base of the tentacles, and partly into the neck and digest- ive canal, — thus serving almost exclusively as retractors of these last.® 1 Milne Edwards, who declares he has seen striated muscular fibres in Eschara (Ann. d. Sc. Nat. VI. 1836, p. 3), must have been deceived. I have been unable to perceive them in Eschara, Al- cyonella, Cristatella, and other species. Nord- mann also has not found them in Cellaria. (Ob- serv. sur la Faune Pontique, 1840, p. 679 ; also Miiller's Arch. 1842, p. ccviii.) The irregular bands appearing during contraction, but afterwards disap- pearing, have been observed by Quatre fanes with Edwardsia (Ann. d. Sc. Nat. XVIII. 1842, p. 84, pi. II. fig. 7, a-b).* 1 Corda, Nov. Act. Acad. C. L. C. Nat. Cur. XVIII. 1839, p. 299. Also Ann. d. Sc. Nat. VIII. 1837, p. 363. * [ § 29, note 1.] Busk has described and figured the striated form of this tissue with Anguinaria spatulata and Notamia bursaria. (Trans. Micro- scop. Soc. of London, II.) I have been unable, however, after considerable search upon many Bry- ozoa, among which were several Alcyonella, to detect any appearances of this kind ; and I would venture a pretty confident opinion that in the spe- 4# 2 Quatrefages, Ann. d. Sc. Nat. XX. 1843, p. 238, pi. IX. fig. 3-5. 3 Quatrefages, Ibid. XVIII. 1842, p. 281, pi. VIII. fig. 3. 4 Bertho/d, Beitr. zur Anat. u. Physiol. 1831, p. 16 ; also in the body of Edwardsia, Quatrefages has found longitudinal and circular fibres (Ann. d. Sc. Nat. XVIII. p. 84). 5 Similar muscles have been observed by Farre (Phil. Trans. 1837, p. 387) in Bowerbankia, Vesi- cularia, Lagenella and other Bryozoa. Milne Edwards has seen them in Tubulipora and Es- chara. (Ann. d. Sc. Nat. VIII. 1837, p. 324 ; VI. 1836, p. 23, pi. I. fig. 1, c, 1, d ; pi. II. fig. 1, a.) Coste has given a very detailed description of the cies examined no such form of muscle is present. Quite lately, however, the subject has been care- fully examined by Allman (Rep. Brit. Assoc. 1850, p. 318), and his descriptions are such as to leave no doubt upon the existence of the striated fibre with the species he has examined, among which are the Paludicellae. — Ed.