110 



visselig som Vaaben til at dræbe de Smaavæsener, der som 

 Næringsmidler fores ind i Gastralhulheden. 



Foruden Mesentérialfilamenter og Acontier ere ogsaa 

 Generationsorganerne bundne til Septa; men om alle ere 

 forsynede dermed, kan jeg ikke afgjøre, da jeg kun har 

 iagttaget dem paa 4. Æggestokkene ligge temmelig langt 

 bag, næsten imod Enden ai' Mesenterialfilamenterne, og 

 have meget tilfælles med dem hos Actinierne. De beståa 

 af lidt fladtrykte, baandformige Oylindre, der slynge sig 

 bagover langs Septumets fri Rand. bundne ved et tyndt 

 Bindevæv til denne og ere i sit Indre beklædte med et 

 Epithel, dannet af runde, kjerneholdige Celler, Tab. XX. 

 Eig. i> c. Æggene, der udvikle sig af Bpithelcellerne, ligge 

 dels to og to sammen, dels enkeltvis og ere i forskjellige 

 Utviklingsstadier. Embryonerne sprænge Æggestokkens 

 Hinder, falde ned i Gastrovascularhulheden. hvor de op- 

 holde sig nogen Tid. for derefter gjennem Øsophagus at 

 drage ud i det Fri. Testiklerne ligge længere bag, omtrent 

 ved Begyndelsen af Physa; de ere yderlig smaa, kun syn- 

 bare gjennem Mikroskopet, have et kamformigl Udseehde, 

 Tab. XX. Fig. it il. irs ere ligesom Æggestokkene ved el 

 lost Bindevæv bundne til Septa, Tab. XX, Fig. 1 1 a, i det 

 Længdefelt, som tindes imellem Længdemuskelen, Tab. XX. 

 Fig. 11 b. og den indre, tildels tri Hand af Septumet. Ved 

 stærk Forstørrelse vise de sig at beståa af en Samling 

 cylinderformede Blindsække, Tab. XX. Fig. 1 i c, hvis ind- 

 vendige Væg er beklædt med runde Celler, hvori en rund 

 Kjerne med sit Kjern elegeme. Tab. XX. Fig. 1 1 d. I 

 Hulheden sees en Samling af mere og mindre udviklede 

 Spermatozoer, der ere pæreformige med et aflangt Hoved 

 og en kort Hale. Tab. XX. Fig. 11 e. De ligge hyppigst 

 to og to sammen, men ogsaa enkeltvis, og synes at dannes 

 af Epithelcellernes Kjerne, da denne i mange Celler havde 

 forhenget sig og nærmet sig Spermatozoernes Form. 



Øsophagus. der er cylindrisk. foldet, indtager i Læng- 

 den omtrent den forreste Trediedel af Gastrovascularhul- 

 heden. og paa den ydre Væg, der er beklædt med et 

 Epithel af eilierende Cylinderceller, Tab. XX. Fig. 12 a, 

 fæster sig 8 Septa. Tab. XX. Fig. 2 c. Indenfor Epithelet 

 er et Bindevævslag, Tab. XX, Fig. 12 b, paa hvis ydre 

 Væg, imellem Epithelet og denne, ligger et Muskellag, be- 

 staaende af Tver- og Længdemuskler, Tab. XX. Fig. 12 c, 

 der ere Fortsættelser af Musklerne paa Septa. Fra den 

 indre Væg af Bindevevet udgaa pyramideformige Eorken- 

 gelser, Tab. XX. Fig. 12 d. der rage ind i Svælgrørets 

 Hulhed. og som bidrage til at danne Folderne her. Disse 

 Bindevævsforlængelser ere beklædte med hoie. eilierende 

 Cylinderceller, imellem hvilke sees hist og her encellede 

 Slimkjertler, Tab. XX. Fig. 12 e. X T ogen Svælggrube findes 

 ikke. heller ikke Andres har fundet nogen saadau : men 

 hos hans Art var Svælgrørets indre Væg glat, imedens det 

 er stærkt foldet hos Edwardsia Andresi. 



These acontia are certainly used heri 1 as weapons with 

 which to kill the small organisms that are passed into the 

 gastral cavity as nutriment. 



Besides mesenterial filaments and acontia. the repro- 

 ductive organs are also attached to the septa, but whether 

 all are furnished with them I cannot determine. as I have 

 only observed them on 4. The ovaries are placed pretty 

 far back, almost at the extremity of the mesenterial fila- 

 ments, and have much in common with those of Actinidæ. 

 They consist of slightly flattened tape-like cylinders that 

 twine themselves backwards along the free margin of 

 the septum. attached to it by a thin connective-tissue , 

 and internally clad with an epithelium formed of round 

 cells containing nuclei (Pl. XX. fig. 9 c). The ova, 

 which develope themselves from the epithelial cells. lie 

 partly two and hvo together, partly singly. and appear in 

 various stages of development. The embryons burst the mem- 

 brane of the ovary and tall into the gastro-vascular cavity, 

 where they remain for some time. aud subsequently pass 

 out into freedom through the æsophagus. The testicles are 

 placed farther back. at about the commencement of the 

 physa; thej are extremely small - only visible under the 

 microscope -- and have a comb-like appearance (Pl. XX. 

 tig. 9 (?) and are. like the ovaries. attached by a loose 

 connective-tissue to the septa (Pl. XX, fig. 11 a) in the 

 longitudinal area which is found between the longitudinal 

 muscle (Pl. XX. tig. 11 //i and the inner, partly free, mar- 

 gin of the septum. Ender powerful magnification they 

 show themselves to consist of a collection of cylindric cæca 

 (Pl. XX. fig. 11 ei. whose inner wall is clad with round 

 cells containing a round nucleus with its nucleus-corpuscle 

 iPl. XX. tig 11 d). ln the cavity there is visible a col- 

 lection of more or le^s developed spermatozoa, pyriform in 

 shape, with an oblong head and a short ta.il (Pl. XX. fig. 



11 p). They, most frequently, lic two and two together, 

 but also singly, and appear to be formed of the nuclei 

 of the epithelial cells. as these had. in many cells, become 

 prolonged and approached to the form of the spermatozoa. 



The æsophagus. which is cylindrical and folded, oc- 

 cupies, longitudinally, nearly the anterior third part of the 

 gastro-vascular cavity. and on its outer wall. which is clad 

 with an epithelium of eiliating cylinder-cells (Pl. XX. fig. 



12 a), 8 septa are attached (Pl. XX. fig. 2 c). On the 

 inside of the epithelium there is a laver of connective- 

 tissue (Pl. XX. tig. 12 6), Upon whose ollter wall. between 

 the epithelium and it. there lies a musculous laver con- 

 sisting of transversal and longitudinal muscles (Pl. XX. 

 fig. 12 c), which are prolongations of the muscles of the 

 septa. From the inner wall of the connective-tissue pyramid- 

 ieal prolongations issue (Pl. XX. fig. 12 (/). which extend 

 into the cavity of the gullet-tube and contribute to the form- 

 ation of the folds in this situation. These connective-tissue 

 prolongations aie clad with high, eiliating cylinder-cells, 

 between which are seen, here and there, unicellular iniic- 

 ous glands i Ml. XX. fig. 12 e). There is no gullet-groove 

 to be discovered, and neither has Andres discovered one, 

 but in his species the inner wall of the gullet-tube was 

 smooth. whilst in Edwardsia Andresi it is strongly folded. 



