236 EDWIN S. GOODRICH. 



After a careful search I found a small ciliated funnel opening 

 into the ccelom, and situated on the narrow stalk a little way- 

 above its point of attachment (figs. 11^ 12, 13, cil. fun.). The 

 blood-vessel which accompanies the stalk (figs. 12 and 13, 

 bl.v.) sends a branch into the lip of the funnel, running im- 

 mediately below the ciliated epithelium, as in many Poly- 

 chsete nephridia. Fig. 13 is a view of a funnel in a still 

 living condition, whilst fig. 14 shows the edge of the lip of 

 another funnel. The cells of which it is composed are vacuo- 

 lated and slightly granular, bear numerous cilia, and occa- 

 sionally irregular processes. Flat ccelomic epithelium covei's 

 the outside of the whole nephridial organ. The internal 

 epithelium is entirely composed of large cells^ protruding far 

 into the lumen, and loaded with " granules " of peculiar struc- 

 ture, to be described farther on. In fig. 21 is represented a 

 fragment of the wall of the nephridium, showing the outline 

 of the cells with the nuclei situated at their base. 



Vejdovsky denies the presence of an internal cavity and of 

 cilia: — " Ein innerer Hohlraum, sowie die Bewimperung 

 fehlen hier ganzlich.^' There can be no doubt that a cavity 

 of considerable size really exists inside the organ. As to the 

 presence of cilia, which is also denied by Rietsch, I must 

 confess that I feel by no means convinced of their absence 

 even in the main sac. When these soft-walled organs are 

 placed under the microscope the cells of the internal surface, 

 which are so full of granules, and bulge inwards into the 

 reduced lumen, become inevitably pressed against each other, 

 and being very thin-walled, they have a great tendency to 

 burst, so that a few scattered cilia would be very difficult to 

 detect. When teased up the cells break off, and present the 

 appearance shown in fig. 23 a. On the other hand, the cells 

 which line the narrow duct leading towards the funnel are less 

 bulky, and preserve their shape better. In this region 1 have 

 seen cilia producing a current from the funnel towards the main 

 cavity of the organ. 



The " granules " filling the cells of the internal epithelium 

 of the nephridium are of curiously complex and quite con- 



