

118 





hvor Snabelen, og bagtil, hvor Glans tager sin Be- 

 gyndelse, — ende blindt, uden at forgrene sig (Fig. 

 10 k, k). De adskille sig saaledes væsentlig fra Sempers 

 Hudkar derved, at de ingen Forgreninger eller Anasto- 

 moser danne, og heller ikke staa i Forbindelse med Ten- 

 takularsystemet. Tager man et Stykke Hud af Sipuncu- 

 lus priapuloides og betragter det fra Indsiden under Mi- 

 kroskopet, saa er Præparatet tyndt og gjennemsigtigt nok 

 til at undersøge de for skj ellige Lag, endog med temme- 

 lig stærk Forstørrelse. Foruden Længde-, Skraa- og 

 Ringmuskellaget med dets Spalter, sees paa Overfla- 

 den med Lethed Peritoneum, kjendeligt ved sin Mus- 

 culatur (fig, 10 p, p). Og over de aflange Spalter i 

 Ringmusculaturen findes aflange Huller i Peritoneum (Fig. 

 10 i, i, i, Fig 4 A, i). Disse Huller ere Indgangene til 

 Længdekarrene (Kefersteins Respirationskar?), hvis Con- 

 turer ved dybere Indstilling kan skimtes under Ringmusk- 

 lerne. End bedre ser man Længdekarrene, naar Cuticula 

 præpareres af, og man betragter Præparatet fra den ud- 

 vendige Flade. Saavel paa et saadant Præparat, som paa 

 Tversnit af Huden parallelt med Ringmusklerne (Fig. 5 rk), 

 findes Karrene liggende udenpaa Ringmusklerne, svarende 

 til Rummene mellem Længdemusklerne. Og endelig kan 

 man paa Tversnit parallelt med Længdemusklerne (Fig. 6) 

 se den directe Sammenhæng imellem Peritonealhulheden 

 (Fig. 6 b) og Længdekarret. Længdekarrenes Vægge 

 (Fig. 4 B) vise ogsaa den samme Bygning som Peritoneum 

 (Fig. 4 A, p, p), ligesom deres indre Flade er forsynet 

 med Cilier paa lignende Maade som Peritoneum. Nogen 

 Forbindelse mellem disse Hudkar og Tentakularsystemet 

 finder ikke Sted, og hos Slægterne Phascolosoma, Onchne- 

 soma og Tylosoma fandtes, saavidt vore Undersøgelser 

 gik, ingen Hudkar. Indholdet af Hudens Længdekar er 

 det samme, som findes i Kropshulheden. Dette Indhold 

 har indtil de allersidste Tider været nøiagtigt undersøgt, 

 og iblandt de Legemer, som findes deri, have de af Krohn, 

 Ehlers, Keferstein, Brandt med Flere beskrevne saakaldte 

 „Tøpfchen" tiltrukket sig en særlig Opmærksomhed. En- 

 kelte Forskere have antaget dem for parasitiske Legemer, 

 medens Andre antage dem for at være bestemte, for 

 Sip unculid erne eiendommelige Organer. E. Ray-Lankester 1 ) 

 har for ganske nylig paavist, at disse „Tøpfchen" udvikle 

 sig paa de contractile Kar, der ere fæstede til Spiserøret, 

 og senere løsrive sig for at svømme frit i Kropshulhe- 

 dens Vædske. — og mener at kunne bevise deraf, at disse 

 Legemer ere Organer, der tilhøre Sipunculiderne, og ikke 

 Parasiter. Vore Iagttagelser give os ikke nogen Anled- 

 ning til at afgjøre Noget med Hensyn til disse Legemer; 

 kun have vi seet, at de ere meget sparsomt tilstede hos 

 de Phascolosoma-Arter, vi have undersøgt. At Cilierne 

 paa disse besynderlige „Tøpfchen" skulle være forsynede 

 med en Knop, som Brandt beskriver dem, under Navnet 

 „Ciliæ vibratoriæ capitatæ", have vi ikke kunnet stad- 



*) The annals and magazin of nat. history XI Vol., 4 Ser-, 

 pag. 89. 



truding itself between the muscular and the epithelial 

 layer, in the form of round vessels, which in front 

 where the proboscis begins, and behind, where the 

 glans begins, terminate blindly without ramification 

 (fig. 10 k, k). They differ then essentially from Semper's 

 cuticular vessels, by forming no ramifications nor anasto- 

 moses; neither do they stand in connexion with the ten- 

 tacular system. If we take a piece of the skin of Sipun- 

 culus priapuloides, aad examine it from the inner side 

 under the microscope, the preparation is thin and trans- 

 parent enough to admit of inspecting the different layers 

 even with a rather strong magnifying power. Besides the 

 longitudinal, oblique and annular muscle-stratum with its 

 fissures, the peritoneum is easily perceived at the surface 

 and is recognisable by its muscular system (fig. 10 p, p\ 

 And above the oblong fissures in the annular muscle- 

 stratum, there are oblong holes in the peritoneum (fig. lo 

 i, i, i, fig. 4 A, i). These holes are the entrances to 

 the longitudinal vessels (Keferstein's respiratory vessels?) 

 the outlines of which can be discerned under the 

 annular muscles. The longitudinal vessels may be seen 

 still better when the cuticle is dissected away, and the 

 preparation viewed from the exterior surface. In such a 

 preparation, as well as in a cross section of the skin 

 parallel to the annular muscles (fig. 5 rk), the vessels are 

 found lying outside of the annular muscles, corresponding 

 to the spaces between the longitudinal muscles. And 

 finally in a cross section parallel to the longitudinal mus- 

 cles, (fig. 6), the direct connexion may be seen between 

 the peritoneal cavity (fig. 6 b), and the longitudinal ves- 

 sel. The walls of the longitudinal vessels (fig. 4 B) 

 exhibit also the same structure as the peritoneum (fig. 

 4 A p, p), as also their interior surface is furnished 

 with ciliæ in the same manner as the peritoneum. No 

 connexion exists between these cuticular vessels and the 

 tentacular system; and in the genera Phascolosoma, 

 Onchnesoma and Tylosoma, so far as our researches went, 

 there were no cuticular vessels to be found. The con- 

 tents of the cuticular longitudinal vessels are the same 

 as are found in the perivisceral cavity. These contents 

 have, up to the most recent times, been minutely exa- 

 mined; and among the substances found there, the so- 

 called „töpfchen", described by Krohn, Ehlers, Keferstein, 

 Brandt and others, have attracted particular attention. 

 Some naturalists have taken them to be parasitical bodies; 

 while others have supposed them to be distinct organs 

 peculiar to the Sipunculidæ. E. Ray-Lankester 1 ) has quite 

 lately demonstrated that these „töpfchen" develop them- 

 selves on the contractile vessels which are attached to 

 the oesophagus, and afterwards detach themselves so as 

 to swim freely in the liquid of the perivisceral cavity; and 

 he is of opinion, that hence these bodies may be proved 

 to be organs belonging to the Sipunculidæ and not para- 



l ) The annals and magazine of nat. history XI vol., 4 ser. 

 pag. 89. 



