STUDIES OX THE E("]'OrAIÎASnTC TREIMATODES OF J.VrAX. 



Ill 



suppose the cells to slirink soon ufter discharo'in,!;' their ronteiils. In 

 these g'oblet-sliaped cells just mentioned I could observe u distinct 

 cell-niembrnne. In the immediate neig'hbourhood of these cells there 

 are in MonocotijJi' numerous lar^-e cells of an irreo'ular sha]>e. each with 

 a rather small nucleus wliich contains a single nucleolus, and with 

 a coarsely granular, well-staiiiing protoplasm destitute of an external 

 meml)rane. Judging from tlieir similarity to the shell-glands of 

 other genera and from the fewness of i\\Q goblet-shaped cells above 

 menti<-)ne(l in the genus under question, T think they are shell-glands 

 wliich are still in the interval in secretory activitv. 



As stated above, the ootyp is characterised l)y the fact tliat it 

 receives the openings of the shell-glands. Tt is, moreover, se])arated 

 from the oviduct by a constriction, which is usually verv distinct — 

 " une sorte de pylore " as P. J.v. lîeneden" calls it. Anteriorly 

 it is in most species directly continued into the uterus without 

 undergoinii- any constriction ; but in many species of Tristoiiiinu ('/'. 

 siinKitiiui, T. ovale, T. hlpaw.'^iticiiin, and T. foliacnnu^ its anterior 

 extremity protrudes into the hinder end of the uterus, just in the 

 same way as the neck of tlie uterus ])rojects into the vagina in the 

 ma.mmalia. ; so that in this genus the uterus and the ootv]) mav be 

 said to be separated from each other bv a valve, which allows a bodv 

 to ])ass from the latter into the ibrmer but not in the contrary direc- 

 tion (PI. XX ir, fig. o). In MoitocoUjle the ootyp opens directly into 

 the genital atrium, the uterus being totally wanting in this genus. In 

 Axinc, 3ïicrocotijJr, OctocotijJe, Dididopliora, and HexacotuJe the wall of 

 the ootyp is not specially different from that of the (niduct; /. c, it con- 

 sists of a thin, homogeneous, protoplasmic layer resting on a basement 

 membrane ; but in some species there is an assemblage of oval nuclei 

 at the entrance of the oviduct (PI. IV, fig. 4). In some cases tliere 



1). p. J. V. Eeneden — Mémoire sur les vers intestinaux, p. 43. 



