320 WILLIAM A. HASWELL. 



termed accessory glands are small, sharply contoured, oval 

 bodies '02 mm. in length, lying one (ac.) on either side of the 

 penis behind the vas deferens. The long axis is directed 

 forwards and inwards, and from the narrower inner end 

 there arises a thin-walled duct, which opens into the 

 sheath of the penis. In the interior of the gland is a well- 

 defined lumen ; the wall is composed of a small number of 

 cells arranged in a single layer, each bulging somewhat in 

 the middle into the cavity. 



Foettinger has failed to recognise the significance of vari- 

 ous parts of the male reproductive apparatus in Histriobdella, 

 owing mainly to his having followed P. J. van Beneden, and 

 taken the claspers for a pair of penes. He describes the 

 seminal vesicles, though without fully recognising their nature 

 or their relations and tracing their ducts (in which he observed 

 sperms) to their union to form a median duct. Of the median 

 structure on which this opens he says, " Celle-ci est cylin- 

 drique et pourvue d'un canal assez etroit qui, d'apres ce que 

 j'ai vu sur le vivant, doit etre le tube impair; elle a une 

 structure peu dechiffrable ; ondirait avoir affaire a un penis." 



The chitinous hollow spine of Stratiodrilus is not repre- 

 sented, but a number of very minute spinules, represented 

 in his woodcut on p. 488, though not referred to in the text, 

 have probably a similar function. 



The granule glands are the cells which Foettinger describes 

 and figures as '^ cellules parietales." With regard to these 

 he states,^ " Au niveau de la partie anterieure de ces vesicules, 

 on voit les cellules parietales qui avoisinent le tube digestif 

 et les muscles dorsaux faire fortement saillie dans le segment 

 et se recourber vers le bas en longeant les extremites internes 

 de leur congeneres. Les parties recourbees sent tres etroites 

 et arrivent a la face dorsale des vesicules ; oil elles se divisent 

 en deux feuillets nuclees formant une sorte de revetement 

 cellulaire." From the figure (pi. 29, fig. 2) to which refer- 

 ence is made it is evident that what are here referred to as 

 the " parties recourbees " are the ducts of the granule 



1 L. c, p. 487. 



