120 



Polyperne ere omtrent 4""" lange, cylindriske, retrak- 

 tile. lidt udvidecle op imod Tentakelskiven og forsynede med 

 8 Ribber, dannede af paatversliggende Spikier; imellem 

 Ribberne sees en svag Linie, der synes at være nøgen, og 

 som antyder Insertionerne for Septa, Fig. 30, b. Opimod 

 Mnndskiven antage Spiklerne en mere skråa Retning, og 

 idet de gaa over paa Tentaklerne, dannes et triangulært, 

 nøgent Felt, hvis spidse Vinkel vender nedad, og i hvis 

 Midte ligger en Række Spikier, der deler Feltet i to Dele, 

 Fig. 30, c. Tentaklerne ere omtrent halvt saalange som 

 Kroppen, temmelig tykke ved Grunden og .paa deres abo- 

 rale Side rige paa Spilder. Pinnulerne ere forholdsvis 

 korte, tykke og ligeledes forsynede med Spilder. Fig. 30. 



Naar Polypen med sin Celle er fuldt udstrakt, og 

 Tentaklerne udslaaede, er Alt temmeligt gjennemsigtigt. 

 og den indtager da en Længde af omtrent 8""", hvoraf 

 mindst 3 mm kommer paa Cellen; men imellem denne og 

 Polypens Bagkrop viser sig cia ingen anden Grændse, end 

 at Ribberne paa Cellen blive noget mindre fremtrædende 

 ved Overgangen til Kroppen, ligesom denne i det Hele 

 tåget er noget mere gjennemsigtig. 



Anatomisk-histologisk Undersøgelse. 



Basalen og Stammen er beklædt med et Ectoderm, 

 der dannes af mange Lag polyædriske Celler, som ere 

 0.007""" i Grjennemsnit med en rund, lidt excentrisk Kjerne, 

 0.002" !m med sit Kjernelegeme, og omgiven af en næsten 

 klar Protoplasmamasse, Fig. 31, a. Cellemembranen er 

 tynd, og i disse Cellelag ere talrige Spikier leirede, 

 Fig. 31, b. Indenfor Ectodermet er et temmelig bredt, 

 hyalint Binclevævslag, Fig. 31, c, hvori Binde vævslegemer 

 og Saftkanaler, og fra hvis indre Flade udgaa Forlængelser. 

 som danne Kanalernes Skillevægge, og hvorved det egentlige 

 Coenenchym, der er spikelløst, fremstaar. Kanalerne ere 

 tapetserede med et Lag Endothelceller, der ere runde med 

 rund Kjerne. 



Polypcellerne, ligesom Polyperne, have et Ectoderm, 

 der bestaar af lignende Celler, som de paa Stammen, men 

 som her synes at ligge i kun to Lag. Fig. 32, a, hvori 

 Spiklerne ligge, Fig. 32. b. Slimkjertler har det ikke været 

 muligt at opdage, hverken paa Stammen eller Polyperne. 

 Indenfor Ectodermet er et ikke meget bredt, hyalint Binde- 

 vævslag, Fig. 32, c, fra hvis indre Flade udgaa d.e 8 Septa, 

 der fæste sig paa Svælget, Fig. 32, d. Septa have som 

 sædvanligt Længde- og Tvermuskler, der gaa over paa 

 Svælgrøret, ligesom Kammervæggene overalt ere beklædte med 

 et Lag runde Endothelceller, lig dem i Stammens Kanaler. 

 Fig. 32, e. Svælgrøret er meget vidt. cylindrisk, forsynet 



The polyps measure about 4""" in length; they are 

 cylindrical, retractile, and somewhat dilated in the proximity 

 of the tentacular disc; they are furnished with 8 ribs formed 

 of transversally placed spicules; a faint line is observed 

 between the ribs, which appears to be bare, and which 

 indicates the insertions of the septa (PL XXI, fig. 30, b). 

 In the proximity of the oral disk, the spicules assume a 

 more diagonal direction and, as they pass over on to 

 the tentacles, a triangular bare area is formed, whose 

 acute angle faces downwards, and in whose middle there 

 is placed a series of spicules that divides the area into 

 two parts (PI. XXI, fig. 30, cj. The tentacles are about 

 half the length of the body, and are pretty thick at the 

 base; on their aboral side they are rich in spicules. The 

 pinnules are relatively short, and thick, and are likewise 

 furnished with spicules (PI. XXI, lig. 30). 



When the polyp, with its cell, is fully extended and 

 the tentacles opened out, the whole is pretty transparent, 

 and then has a length of about 8""", of which, at least 

 3""" are taken up by the cell ; but between the cell and 

 the posterior body of the polyp there, then, appears no 

 other margin than, that the ribs of the cell become some- 

 what less prominent at the transition to the body, whilst, 

 also, the latter altogether becomes somewhat more trans- 

 parent. 



Anatomo-histological Examination. 



The base and the stem are clad with an ectoderm 

 that is formed of numerous layers of polyhedrical cells 

 measuring 0.007'"'" in diameter, and which contain a globular, 

 somewhat eccentrically placed nucleus, measuring 0.002 mm , 

 their nucleus body being surrounded by an almost pellucid 

 protoplasmic substance (PL XXI, fig. 31, a). The 

 cellular membrane is thin, and in these cellular layers 

 numerous spicules are embedded (PL XXI, fig. 31, b). 

 Inside of the ectoderm, there is a pretty broad, hyaline 

 connective-tissue layer (PL XXI, fig. 31, c), in which con- 

 nective-tissue corpuscles and nutritory ducts are found, and 

 from whose inner surface prolongations issue and form 

 the divisional walls of the ducts, and by whose means the 

 sarcosoma-proper — which is devoid of spicules — is pre- 

 sented. The ducts are coated with a layer of endothelial 

 cells, which are globular and contain globular nuclei. 



The polyp-cells, and the polyps as well, have an ecto- 

 derm composed of cells similar to those of the stem, but 

 which appear, here, to be placed in only two layers 

 (PL XXI. fig. 32, a) in which the spicules are situated 

 (PL XXI, fig. 32, &). It has not been possible to 

 detect mucous glands either upon the stem or the polyps. 

 Inside of the ectoderm, there is a not very broad hyaline 

 connective-tissue layer (PL XXI. fig. 32, c), from whose 

 inner surface the 8 septa, which attach themselves to the 

 gullet, issue (PL XXI, fig. 32, d). The septa have, as 

 usual* longitudinal and transversal muscles which pass over 

 on to the gullet-tube, whilst, also, the chamber-walls are 



