238 OLIGOCHAETA 



the duct ; in many other forms this is still further emphasized by a constriction which 

 divides the two regions of the spermatheca referred to ; this constriction is especially 

 well seen in Clitellio, in which genus both Clapaeede and myself have figured it. 

 In Hemitubifex insignis Eisen has figured the spermatheca as if there were cilia in 

 the duct, but there is no mention of this in the text ; they may be intended to 

 represent spermatozoa; cases where the spermathecae are ciliated are extremely 

 rare, and, perhaps, a little doubtful. However, Nassb distinctly asserts the presence 

 of cilia in the duct of the spermatheca of Tuhifex: 'Im Ausfuhrungsgange tragt das 

 Epithel eine Cuticula und flimmert.' On the other hand, Vejdovsky has denied this 

 ciliation, nor is' it figured by Stolc (3). ■ Between the peritoneal coat and the lining 

 epithelium, two muscular layers are developed, particularly at the end of the organ 

 nearest to the opening ; this region of the spermatheca can often, as in Tuhifex, be 

 extruded. The spermathecae often, as in Clitellio and Hesperodrilus, extend through 

 several segments. Bothrioneuron has no spermathecae at all. The spermatophores 

 have been already described. 



The oviducts of the Tubificidae were first discovered by Stolc (4) ; this naturalist 

 found them in the genera Ilyodrilus and Psam'moryctes ; a little later I found these 

 organs in Clitellio and in Hemitubifex; later still Stolc figured the oviducts of 

 Bothrioneuron ; finally, I have found them in the genera Branchiura and Hesperodrilus. 

 There is now a considerable probability that in all Tubificidae there are a pair of 

 oviducts opening by a comparatively large funnel into the eleventh segment (or 

 twelfth in Hesperodrilus), and on to the exterior on the boundary line between this 

 • segment and the following. 



Previously to the discovery of the true oviducts a :^ost curious view was prevalent as to the 

 nature of the oviducts of the Tubificidae, which is of interest as an instance of the persistence 

 of an error that had nothing in particular to recommend it ; the view in question was in fact 

 neither probable nor ingenious. They were originally believed to be connected with the male 

 efferent apparatus; d'Udekem (6) described the egg-sac as a 'matrix,' communicating, on the one 

 hand, with the ovaries, and, on the other hand, opening into the 'cloaca,' which was the name 

 given by him to what we now call the atria ; d'Udekem speaks of the ' matrix ' opening into the 

 cloaca, but in the next paragraph he states, and his statement is illustrated by a figure, that the 

 wall of this sac forms the outer wall of the cloaca ; hence the oviduct, according to this view, 

 surrounds the atrium, which is thus invaginated in it. CLAPARiiDE (2) spoke of this description as 

 being 'sans doute exacte '; but he limited his support of d'Udekem's statements to the enclosure of 

 the atrium within the oviduct ; he denied any connection between the oviduct and the egg-sac. 



Vejdovsky (13) originally ranged himself on the side of d'Udekem and CLAPAKiiDE, and 

 supported their views by his discovery of eggs passing out of the supposed oviducts ; later, however, 

 he gave reasons for believing that these bodies were not ripe eggs at all, but immature egg-cells 

 detached from the ovary by the compression of the cover-glass, and abandoned the belief that 

 the oviduct of the Tubificidae was in the position assigned to it by his predecessors. Grranting 



