126 



kornet Masse, uden at nogen Kjerne kan iagttages i dem og 

 ligne meget de hvide Blodlegemer hos de høiere Dvrklasser. 



Polypkroppen er udvendigt beklædt med et Ectoderm, 

 meget ligt det, som tindes paa Stammen og Grenene, 

 Fig. 4, a, og hvori encellede Slimkjertler og Spilder ere 

 leirede. Indenfor Ectodermet er et Bindevævslag, Fig. 4, e, 

 der svarer fuldkomment til det, som er beskrevet ved 

 Stammen. Det samme Maskenæt tindes her; Maskernes 

 Vægge ere overtrukne med Ectodermceller, Fig. 4, c, og 

 Hulhederne fyldte med Spikier. Fra Bindevævets ind- 

 vendige Flade udgaa. 8 Septa, der fæste sig paa Svælget 

 og danne Kamrene. Muskelanordningen paa Septa er som 

 sædvanlig ; ligeledes ere Kamrene overalt ibrsynede med et 

 Lag runde Celler med Kjerne og Kjernelegeme, Fig. 4. /. 



Svælget er langt, cylindrisk, uden Spilder, Fig. 5, a; 

 paa dets indre. Flade er langs Bugsiden en temmelig vid, 

 halvrund Svælgrende, forsynet med lange Pidskeceller, Fig. 

 4, g; den øvrige Del af Svælget er beklædt med cilierende 

 Celler, hvoraf de i den øverste Del nærme sig meget Ecto- 

 dermcellerne uden at være saa kantede, imedens de i den 

 nedre Del maa betragtes som Cylinderceller. Overalt i 

 Svælgepithelet, naar undtages Svælgrenden, er indplantet 

 dels pæreformige, dels ægformige, encellede Slimkjertler i 

 temmelig stor Mængde; Fig. 4, li. Disse Slimkjertler have 

 en smal Udførselsgang, der muncler ud i Svælghulheden. 



Kjønsorganeme sidde langt nede i Mavehulheden og, 

 som tidligere nævnt, træffes de ogsaa i Kanalerne saavel 

 i Stammen som i Grenene og have den samme Bygning, 

 som oftere er omtalt. Kjønnet er adskilt. Hos flere 

 Polyper vare Embryonerae endnu indesluttede i Ægget, 

 hvor de laa stærkt bøiede, Fig. 6; hos andre [havde de 

 forladt Ægget, laa frit i Mavehulheden, vare temmelig 

 lange, ormformige, overalt beklædte med Cilier og forsynede 

 med Gastrulamave og Mund. Hos disse frigjorte Embryoner 

 iagttoges endnu ikke nogen Spikeldannelse, saaledes som 

 Tilfældet var hos Embryonerne af Slægten Nephthya, og 

 der er Grund til at antage, at Spiklerne først optræde, 

 efter at Ungen har forladt Moderen for at føre et selv- 

 "stændigt Liv; thi hos en Polyp var netop en saadan 

 spikelløs Unge ifærd med at passere igjennem det trange 

 Svælg for at paabegyncle sit individuelle Liv, Fig. 5, /;. 



Paa Basaldelen ligge Spiklerne pakkede paa hver- 

 andre, og de hyppigste Former, hvorunder de her optræde, 

 ere Firlinger, Dobbeltstjerner og Spindler. Firlingerne 

 ere meget forskjellige, kors-, timeglas- eller rosetformede ; 

 de ere dels glatte, dels svagt besatte" med Papiller, dels rigt 



the ducts have, partly, the same form, size, and substance 

 as the endothelial cells or, partly, they are a little 

 different from them, owing to their being filled up with a 

 granular mass in which no nuclei can be detected, and 

 much resembling the white blood-corpuscles found in the 

 higher classes of animals. 



The polyp-body is, externally, clad with an ectoderm 

 much resembling that found on the stem and the branches, 

 (fig, 4, a), and in which unicellular mucous glands and 

 spicules are embedded. Inside of the ectoderm, there is 

 a connective-tissue layer (fig. 4, e) which exactly corre- 

 sponds with that described in connection with the stem. 

 The same reticulation of meshes is found here; the walls 

 of the meshes are coated with ectodermic cells (fig. 4. c), 

 and the cavities are filled with spicules. From the interior 

 surfaces of the connective-tissue, 8 septa issue and attach 

 themselves to the gullet, and form the ducts. The muscu- 

 lar arrangement on the septa is the usual one, and the 

 chambers are, also, everywhere supplied with a layer of 

 globular cells containing nucleus and nucleoli (fig. 4, /). 



The gullet is long, cylindrical, and devoid of spicules 

 (fig. 5, a). On its inner surface, along the ventral side, 

 there is a pretty wide, semi-circular, gullet-passage furnished 

 with long flagelliform cells (fig. 4, g). The remaining part 

 of the gullet is clad with ciliated cells, of which, those in 

 the uppermost part approach much, in form, to the ecto- 

 dermic cells, without, however, being so angular, whilst 

 those in the lower part must be considered to be cylinder- 

 cells. Everywhere, in the epithelium of the gullet, with 

 exception of the gullet-passage, there are planted, partly 

 piriform, partly oviform, unicellular mucous glands in 

 pretty great abundance (fig. 4, li). These mucous glands 

 have a narrow excretory duct which opens into the gullet- 

 cavity. 



The generative organs are placed far down in the 

 gastral cavity, and, as previously stated, they are also met 

 with in the ducts of, both, the stem and the branches, and 

 have the same structure as that already frequently spoken 

 of. The sexes are separated. In many polyps, the em- 

 bryons were still enclosed in the ovum, where they lay 

 strongly curved (fig. 6). In others, they had emerged from 

 the ovum and lay loose in the gastral cavity, appearing 

 pretty long, flat and' vermiform, and clad all over with ciliæ ; 

 and also furnished with a true gastrula stomach and mouth. 

 In these independent embryons, no spicular formation was 

 yet visible, like the case of the embryons of the genus 

 N&phthya, and there is reason to suppose that the spicules 

 first appear after the young one has abandoned the mother 

 in order to lead its independent life, because, in one polyp, 

 one of these spicule-free young ones was just engaged in 

 passing through the narrow gullet in order to start upon its 

 individual existence (fig. 5, h). 



In the basal part, the spicules are placed packed 

 upon each other, and the most frequent forms in which 

 they appear, here, are quadruplets, bistellates and fusees. 

 The quadruplets are very various in form, as they are met 

 with in cruciform, sand-glass form, or rosetiform ; they 



