120 



Polypeme ere omtrent 4 lange, cylindriske, retrak- 



tile. lidt udvidede up iniod Tentakelskiven og forsynede med 

 8 Ribber, dannede af paatversliggende Spikler; imellem 

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

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

 Mundskiven antage Spiklerne en niere 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 Spikler, 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 Spikler. Pinnulerne ere forholdsvis 

 korte, tykke og ligeledes forsynede med Spikler. Fig. 3<>. 



Naar Polypen med sin Celle er fuldt vidstrakt, og 

 Tentaklerne udslaaede, er Alt temmeligt gjennemsigtigt, 



og den indtager da en Længde af omtrent s hvoraf 



mindst 3""" kommer paa Cellen; men imellem denne og 

 Polypens Bagkrop viser sig da ingen anden Grændse, end 

 at Ribberne paa Cellen blive noget mindre fremtrædende 

 ved < (vergangen til Kroppen, ligesom denne i det Hele 

 tåget er noget mere gjennemsigtig. 



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

 cylindrical, retractile, and somewbat 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 tu he hare. 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 hare åren 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 (Pl. XXI. fig. 30. c). The tentacles are about 

 half the length of the body. and are pretty tbick at the 

 hase: on their aboral side they are rich in spicules. The 

 pinnules are relatively short. and thick, and are likewise 

 furnisbed with spicules (Pl. XXI. fig. 30). 



Wheii tile polyp, with its cell. is fully extended and 

 the tentacles opened out. the whole is pretty transparent, 

 and then lias a length of about 8""", of which. at leasl 

 li""" are tåken up by the cell: hut between the cell and 

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

 other margin tban, that the ribs of the reil become some- 

 wbat less prominent at the transition to the body, wliilst. 

 also. the latter altogether becomes somewbat more trans- 

 parent. 



Anatcmisk-histologisk Undersøgelse. 



Basalen og Stammen er beklædt med et Ectoderm. 

 der dannes af mange Lag polyædriske Celler, som ere 

 0.007""" i Gjennemsnit med en rund. lidt excentrisk Kjerne. 

 0.002™'" med sit Kjemelegeme, og omgiven af en næsten 

 klar Protoplasmamasse, Fig. 31. a. Cellemembranen er 

 tynd, og i disse Cellelag ere tallige Spikler leirede, 

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

 byalint Bindevævslag. Fig. 31. <■. hvori Bindevævslegemer 

 og Saftkanaler, og fra hvis indreFlade 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 Polypeme, 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 Polypeme. 

 Indenfor Ectodermet er et ikke meget bredt, byalint Binde- 

 vævslag, Fig. 32. r. fra hvis indreFlade udgaa de 8 Septa. 

 der fæste sig paa Svælget, Fig. 32, il 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 



Anatomo-histologica! Examination. 



The hase and the stem are clad with an ectoderm 

 that is formed of numerous lavers of polyhedrical cells 



measuring 0.007 in diameter and which contain a globular, 



somewhat eccentrically placed nucleus, measuring 0.002""", 

 their nucleus body being surrounded liv an almost pellucid 

 protoplasmic substance (Pl. XXI. li". 31, a). The 

 cellular membrane is thin. and in these cellular lavers 

 numerous spicules are embedded (Pl. XXI. fig. 31. b). 

 Inside of the ectoderm. there is a prettj hroad. hyaline 

 connective-tissue layer (Pl. XXI. fig. 31. r), in which con- 

 nective-tissue corpuscles and nutritory ducts are found. aud 

 from whose inner surface prolongations issne and form 

 the divisional vyalls of the ducts. and 1>\ 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 glohular nuclei. 



The polyp-cells. and the ])olyps as well, have an ecto- 

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

 which appeai-. here. to he placed in only two layers 

 (Pl. XXI. fig. Ml', a) in which the spicules are situated 

 (Pl. XXI. fig. 32. b\. 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 laver (Pl. XXI. fig. 32. r), from whose 

 inner surface the < s 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 



