G5G THE MARINE ANNELIDES OF THE ORDER SERPULEA, 



organs" of other Annelides (1), and he regards excretory ducts 

 for the generative products as being entirely absent, — the ova 

 and spermatozoa escaping either by rupture or through simple 

 apertures in the body wall (2). 



The true " segmental organs," however, which seem hitherto 

 to have escaped notice, are entirely distinct from these large 

 " glandes tubipares," or " organes segmentaires " of Claparede- 

 They are found in pairs in all the segments of the abdomen. 

 They consist of pyriform sacs (pi. XXXIV., fig. 6), densely 

 ciliated internally and with very delicate colourless walls. These 

 sacs open externally on the sides of the segments by slit-like 

 apertures bordered by strong cilia, and, presumably, open also 

 internally into the body cavity, though I have not succeeded in 

 finding the internal opening. A somewhat unusual circum- 

 stance in connection with these organs is that, in Eupomatus 

 elegans at least, they serve not only as efferent ducts for the 

 genei ative products, but also as seats of development of the ova. 

 In that species I found in the cavity of each segmental organ a little 

 clump of ova in all stages of development, from the transparent 

 immature cell to the perfectly developed ovum, with its granular 

 interior and characteristic reddish pigment. The little group of 

 ova in the interior of each segmental organ were closely adherent 

 together, and i-otated round and round under the action of the 

 cilia. Alternating with the segmental organs were the true 

 ovaries consisting of clumps of ova in various stages of develop- 

 ment and occupying the ordinary position. In the male speci- 

 mens examined I have always found the sacs empty. 



These segmental organs of Eupomatus are of an extremely 

 simple type ; but organs of equal simplicity are known to occur 

 in other forms, e. g. Scoloplos (3.) The discovery of the ova in 

 their interior places their function beyond a doubt, though at the 

 same time from the mode of their occurrence as a free group of 



(1) L.c, p. 132. 



(2) " II est certain qu'il ne se presente mil part chez les Serpulicns 

 d'organes segmentaires dc la forme typique," 1 c , p. 135. 



(3.) Mau, Zeitscrift fiir Wiss. Zool, Band XXXVI., p. 3S9, 



