2Q2 s. GOTO. 



much like the albuminous substance conüiined in the egg-capsules of 

 the earthworm and other animals when coagulated ; and the wall was 

 completely shrunken, apparently owing to the great secretory activity 

 which produced the coagulum. 1 have not, however, been able to 

 study the minute structure of the gland in this genus owing to 

 scantiness of the material and its imperfect ]3reservntion ; and I must 

 therefore content myself with the above meagre account. What von 

 Linstow'^ calls the " Samenblase" in PhyUine Houlorffii and V. J . v. 

 Jjeneden"' the " vésicule séminale" situated outside the penis in E. 

 Hip])Otjlossi, is imdoubtedl}' the prostate gland. I nlso think that 

 what St.-Remy^' culls the "vésicule prostatique accessoire" is nothing 

 else than a })(jrtion of the ])rostate gland which seems, in VhijUomlla 

 sûleœ according to that writer's account, t(,) consist of numerous 

 lobes. 



In Tristonuuii, tlie prostate gland is much developed and has been 

 already observed by my predecessors. It consists of mimerons unicell- 

 ular glands with exceedingly long necks, which in some species, e. (j., 

 Trisl. foliaccam, are arranged distinctly in two separate gr(3ups 

 (I'l. XXA^, hg. [)). The cells themselves are scattered without any 

 order througli the mesenchyma of the median and lateral portions of 

 the Ijody around the foremost part of the vas deferens (PI. XXII, 

 fig. 1). They present somewhat different aspects according to the dif- 

 ferent states of their secretory activity. They are either polygonal or 

 spheric'il, 1)ut are of very different sizes ; the smaller ones stain 

 deeply and their protoplasm is finely granular, while the larger ones 

 have a more coarsely granular and more weakly staining protoplasm. 

 The nucleus is always very distinct ; it is vesicular, and contains 



1). Von Linstow — Beitrag zur Anatomie von Phylline Hendorffii. Archiv f. mik. Ana- 

 tomie, Bd. 33, 1889, p. 171. 



2). P. J. V. Beneden — Memoire sur les vers intestinaux, p. 29 & PL III, fig. 1. 

 3). St.-Eemy — Etude de l'appareil génital chez les Tristomiens, p. 17. 



