BY WILLIAM A. HASWELL, M.A., B.SC. 657 



ova in various stages, adding an element of perplexity. It would 

 seem to afford additional evidence in favour of the theory that 

 the ova may be developed from the corpuscles of the perivisceral 

 fluid. 



The so-called tubiparous glands were noticed by Huxley in 

 Protula Dysteri. They were described by Quatrefages, curiously 

 enough, as hepatic caeca, "similar in their relations to the hepatic 

 caeca of the Aphroditea (1.) They were examined more minutely 

 by Clarparede, by whom, as above noticed, they were regarded 

 as the sole equivalents in this family of the segmental organs. 

 Clarparede directs attention to a great difference which he 

 considers to exist in their disposition in the Sabellidas and in the 

 Serpulidse. In the former family, he states, each " tubiparous 

 gland " has the form of a tube bent on itself, the two branches 

 being cemented together. These two branches are of very 

 unequal dimensions ; the narrower, which is also internal, 

 opening into the perivisceral cavity ; the other enlarges 

 into a wide sac which gradually becomes narrowed to form the 

 excretory duct, opening at the base of the first parapodium. 

 In the Serpiduke, on the other hand the tubiparous glands of 

 opposite sides unite to form a common mesial excretory duct 

 which opens in front between the bases of the branchiae (2.) 



I have only examined the tubiparous gland in one species of 

 the Sabellidse, a species of Sabella, and I find that, so far from 

 according with Claparede's description, the gland has exactly the 

 relations which it has in the Serpulidse. The common duct opens 

 in the usual situation ; it early bifurcates, the two branches 

 running close to one another for a short distance. In this 

 situation the efferent ducts are lined by an epithelium which 

 consists of extremely low flat cells with granular contents and 

 with long flagella. 



Within the limits of the family Serpulidee itself I have found 

 considerable variations in the form and structure of these organs. 

 The simplest form is presented by Eupomatm, and in Serpala the 

 arrangement is closely similar. In these genera each gland 



(1) Hist. N. des Ann6l£s, t. I., p. 49. 



(2) I.e., p. 133. 



