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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    CHAPTEll VIII. ORGANS OF SECRETION. § 161. Many Annelides are covered with a mucus which is secreted by small, simple follicles situated in the skin.'1' The calcareous tubes of the Serpulini, appear to be secreted by a collar surrounding the first segment of the body.® It is not yet decided that the leathery tube in which many other Branchiati are concealed,® is secreted by an analogous organ. Those Oapitibranchiati which form tubes with grains of sand, bits of shells, &c., have, perhaps all, an opening close behind the mouth upon the ventral surface. This opening is in connection with many glands situated at the anterior extremity of the body, which probably secrete a substance for the gluing together of the materials of these tubes.® CHAPTER IX. ORGANS OF GENERATION. §162. The Annelides reproduce partly by by a sexual apparatus. l Similar muciparous follicles are arranged in curved rows with the Hirudinei, upon both the ven- tral and dorsal surfaces, giving the skin a granu- lated aspect 5 see Brandt, Med. Zool. II. p. 244. I have seen similar groups of follicles with the larger Lumbricini.* v The secretion of the calcareous matter occurs here probably as upon the border of the mantle of Mollusks. 3 Sabella, Onuphis, and Ckaetoptcrus. 4 As secreting organs of this glue, Rathkd has correctly described four yellowish glands situated, * [ § 161, note 1.] Ley dig (Siebold and Kblli- icer's Zeitsch. 1849, p. 109) has described with Pis- cicola, Clepsine, Nephelis, and other Hirudinei, cutaneous glands. These consist of an infundibu- liform sac, which, exactly resembles a nucleated cell, from which passes off a long, tortuous duct. a transverse nssuration, and partly with Amphitrite, upon the ventral surface of the first and second segment of the body, and opening by a common canal at the first seg- ment •, see Danzig. Schrift. loc. cit. p. 71, Taf. V. fig. 6, aa. fig. 2, d. With Terebella, and Sa- bella, the two glands near the cephalic extremity, are perhaps of the same nature. Grube, however, thinks them male genital organs ; see, Zur Anat. d. Kiemenwiirmer, ]>. 31, Taf. II. fig. 12, y.5 and Milne Edwards, Ann. d. Sc. Nat. X. 1838, PI. X. n. PI. XI. fig. 1, h. fig. 2, f. With Piscicola, these are situated in the cephalic and pedal shield, but in Clepsine, and Nephelis, they are also present in the skin throughout $ see loc. cit. Taf. VIII. fig. 23. This structure is re- markable from its resemblance to some of the cuta- neous glands of the liigher animals.— Ed.