ORDERACTINOIDEA. 37 



as represented in figure 18, which had spontaneous motions. They 

 were not frequently seen, and some doubt remained as to their origin. 



The nature of these cords has long been a subject of speculation. 

 The most prevalent opinion has been that they were connected with 

 the process of digestion, and they have been called biliary vessels and 

 cseca. They have' also been considered oviducts* and ovaries. f 

 Wagner first ascertained their spermatic character, and the general 

 structure of the filaments : yet Dicquemare distinctly states their 

 resemblance to " spermatic vessels," and says, that they probably 

 contain bulbs or buds, " which open in time, and, cleaving to the 

 bodies in which these threads are extended, produce small ane- 

 monies."^ Dr. Wyman has the honour of originality in his re- 

 searches, and the remarkable results throw some new light upon the 

 structure of these spermatic organs. There is still uncertainty with 

 regard to the functions of the parts observed. The forms represented 

 in figures 19 a, b, c, have nearly the ordinary appearance of sperma- 

 tozoa. But if the last-mentioned (figure 18) are the true spermatozoa, 

 of which there is much doubt, the others, he suggests, may possibly 

 be Spermatophora, as they have some resemblance (especially b, c) to 

 the organs of this nature in the Cephalopoda, represented by Milne 

 Edwards : but he ventures no decided opinion without farther inves- 

 tigation. 



These spermatic cords appear to undergo a periodical increase and 

 absorption, as is the case with the spermatic organs of most animals; 

 for, at times, their length is very much less than at others. 



28. Between the spermatic lamellaB are others of similar situation, 

 which are ovarian. Like the " white cords," the ovaries grow from 

 the margin, and form a series of clusters in two ranges, which fringe 

 the lamella?, or, when large, fold back and lie in the spaces between 

 them. Figure 20 shows the double line of clusters, as they were seen 

 attached to the margin of an ovarian lamella in the Actinia marginata. 



* Sharpey, Cyclop. Anat. and Physiol., i. 416. 



\ Cuvier's Reg. Anim., iii. 290 ; Amer. Ed., iv. 388. Also, A. de Quatrefages, Sitr 

 Ics Edwards ies, Ann. des Sci. Nat., xviii. (1842) 65. The spermatic cords and sperma- 

 tozoa arc well figured. 



J Wagner, Sur la Generation, Ann. des Sciences Nat., viii. (1837) 282, and Wige- 

 mann's Archives, ii. 215 (1835). Also, Milne Edwards, Ann. des Sci. Nat., xiii. (1840) 

 196, on the Structure and Sexual Organs of the Dendrophyllia. 



Phil. Trans. Abridg., xiii., 6:J9, 1775. 



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