54 EDWIN S. GOODRICH. 
particles from the celomic fluid than to propel it down the 
canal, 
Passing backwards from the nephrostome is the nephridial 
canal (neph. c., figs. 2, 3, and 5). I may say at once that, 
although I have not been able to follow it throughout its whole 
extent with certainty, owing to the opaque and granular nature 
of the post-septal region and the small dimensions of the 
tortuous lumen, I believe the main duct to be continuous and 
single (i.e. without anastomosing branches), except in that 
region which leads directly to the exterior, where the lumen 
occasionally undergoes secondary subdivision (figs. 2 and 7). 
Although, therefore, I cannot claim to be able to prove the 
unbranched character of the canal, yet amongst the number of 
Enchytreid nephridia I have had under observation during 
the last three or four years I have never come across a single 
undoubted case of such anastomosing. The course of the canal 
drawn in fig. 2 does not profess to be accurately represented in 
all its details, nevertheless I have been able to observe that at 
least the main features of the canal’s course, if not the less 
important of its convolutions, are constant, not only in the 
different nephridia of the same worm, but also in the nephridia 
of different individuals of the same species. For the first part 
of its course it has a very narrow lumen, and is not ciliated. 
It then widens slightly, and undergoes several complicated 
twists in the more posterior and dorsal region of the main body 
of the nephridium. It is along this second region of the canal 
that here and there we find a slight oval enlargement of the 
lumen, in which is situated a bunch or “ flame” of cilia (ce. a., 
fig. 2), similar to the “flame” in the nephrostome, and con- 
stantly driving the liquid in one direction, namely, to the 
exterior. As far as I can make out, there are no more than 
1 Anyone examining the living worm could hardly miss seeing these cilia. 
It is, of course, just possible that the worms observed by M. Bolsius were of 
exceptional structure, but I am more inclined to think that he was misled, 
both with regard to the absence of cilia and the anastomosing of the canal by 
employing the method of sections alone. 
