1890 ] Annelid Descent. 1151 
by the undoubtedly separate origin of the middle excretory por- 
tion of the permanent organ (as in Psygmobranchus), which does 
not come from the peritoneum. It is to be especially emphasized 
that I would leave entirely out of the question the statements 
regarding the occurrence of longitudinal canals in Annelids : that 
concerning Polygordius as not confirmed by any of the subse- 
quent studies, and my own concerning Lanice as being much 
more likely a secondary than a primitive condition, contrary to 
my former unpublished opinion. Yet for my part I still believe, 
in spite of the criticism of this conception by Berg, with its quite 
unnecessary and unbecoming additions, that the nephridial tubes 
are to be regarded as parts of a pair of longitudinal canals, such 
as the Turbellarians have; in which, in consequence of inter- 
segmental constriction of the body, the excreted fluid was checked, 
and first gave rise to segmentally arranged openings, after which 
an ultimate division into segmented sections could take place. 
To the canals, that were primitively closed internally and pro- 
vided with fine side branches and end cells, were added in Anne- 
lids new structures in the shape of peritoneal funnels. Thence 
the mode of action of the organ gradually, though not radically, 
changed considerably, and the entire original terminal portion 
quite disappeared, as being superfluous. Regarding the original 
signification of the nephridial funnels, we must bear in mind that 
the segmentation of the primitively uniform pair of sexual glands 
must give rise to a corresponding number of paired discharging 
channels for the sexual products. As in Nemerteans, these could 
appear as centrifugal outgrowths of the follicle wall, and in many 
cases they may have met the metameric nephridial tubes (instead of 
reaching the skin directly), have joined to them so that eggs and 
sperm were discharged from the body, and thus have been trans- 
formed into nephridial funnels.’ 
3.5.14 3$. 14i fA 
9 Berg formerly expressed th ion that th 
canals for the sexual products, and arose originally from the walls of the sexual follicles, 
In my opinion, this idea is justified only in the above restricted form only} in reference 
to the nephridial funnels. Moreover, Berg in accepting Kl berg ption of the 
berg there are no mesodermal somites comparable to the Nemertean gonads. Yet he 
affirms that he has retained his opinion of the Annelid nephridium unchanged. An ex- 
planation seems necessary ! 
