132 



Anatomisk-histologisk Undersøgelse. 



Stammen, elet vil sige de sammenvoxede Polypceller, 

 er udvendigt beklædt med et Epithel, bestaaende af 2—3 

 Lag polyædriske Celler, jder ere 0,006""" og have en lidt 

 excentrisk Kjerne med Kjernelegeme, omgiven af en tem- 

 melig sparsom Protoplasmamasse, Tab. XX, Fig. 1, a. 

 Imellem disse Ectodermceller sees hist og her pæreformige, 

 encellede Slimkjertler, lig dem, der tidligere ere beskrevne, 

 samt en Mængde Spikier, Tab. XX, Fig. 1, a. Dette gjælcler 

 dog kun de ydre Vægge af Polypcellerne. De indre ere 

 sammenvoxede og [uden Ectoderm, Tab. XIX, Fig. 49. 

 Sammenvoxningen er saa intim mellem 2 og 2 Cellers Binde- 

 vævslag, Fig. 49, a, at dette ikke er tykkere, men endog 

 noget tyndere |end den ydre Vægs Bindevæv, Fig. 49, 6, 

 hvori der iagttages Bindevævslegemer med Udløbere og fine 

 Ernæringskanaler. forsynede med Epithel; Binclevævet er 

 hyalint. Der. hvor 5—6 Celler støde sammen, er gjerne 

 et noget bredere, hyalint Bindevæv, hvori sees 2 større, 

 runde Ernæringskanaler, beklædte med Epithel. hvilke gaa 

 igjennem hele Stammen og synes at danne det egentlige 

 Coenenchym eller Forstøtningsmaterial for Kolonien, Fig. 

 49, c. Betragter man hele Zoanthoclemet som bestaaende 

 af en Stamme, hvorfra Polyperne udspringe, saa svare de 

 sammenvoxede iVægge af Polypcellerne til Skillevæggene, 

 der danne Hovedkanalerne hos Alcyoniclerne i Almindelig. 

 hed; men som man ved, er der altid hos disse et større 

 eller mindre udbredt Coenenchym imellem Kanalerne, 

 imedens her intet saaclant tindes. Det er ogsaa denne 

 store Mangel paa Coenenchym som gjør, at hele Zoantho- 

 demet, naar Polyperne ere fuldt udstrakte, er ganske gjen- 

 nemsigtigt og meget bøieligt. 



Paa den indre Flade af Polypcellens hyaline Binde- 

 væv sees i hele Længclen 8 listeformige Fremspring, som 

 ere de fra Polypkroppen udgaaende Septula, der strække 

 sig lige til Cellens (den forlængede Mavehulheds) Bund, 

 Fig. 49, d, Til 2 af. disse Septulers Rand ere de dorsale 

 G-astralfilamenter^ fæstecle. Septula ere forsynede med 

 Muskelfibre, som ere saaledes ordnede, at cle paa den ene 

 Side danne Længde- og paa den anden mere paaskraas 

 gaaende Muskler; begge Muskellag, ligesom hele den ind- 

 vendige Flade af Polypcellerne, er beklædt med et Endothel, 

 der dannes af et Lag meget smaa, runde, temmelig klare 

 Celler med Kjerne og Kjernelegeme. Paa enkelte Tver- 

 snit syntes det, som om hele den indre Flade havde 

 Muskelfibre, der vare meget spredte, men som paa Septula 

 samlede sig til Længde- og Skraamuskler, og det tør vel 

 hænde, at dette Forhold er det rette. Enhver Celle 

 strækker sig ned til Basaldelen, der danner dens Bund, 

 og imedens den øverste Del er ganske afsluttet, saa er 



Anatomo-histological Examination. 



The stem, that is to say the concreted polyp cells, 

 is externally clad with an epithelium, consisting of 2 — 3 

 layers of polyhedrical cells measuring 0.006"™, and con- 

 taining a somewhat eccentric nucleus with nucleolus, sur- 

 rounded by a pretty thin protoplasmic mass. Between 

 these ectoderm cells there are, here and there, seen, piri- 

 form, unicellular, mucous glands like those which have been 

 previously described, and also a multitude of spicules 

 (PL XX, fig. 1, a). That refers, however, only to the 

 external walls of the polyp-cells; the inner walls are 

 concreted together and have no ectpderm (PI. XIX, 

 fig. 49). The concretion is so intimate between the con- 

 nective-tissue layer of double pairs of cells (that is 2 and 

 2 cells) (PI. XIX, fig. 49, a), that the layer is no thicker, 

 but even somewhat thinner, than the connective-tissue of 

 the outer Avail (PI. XIX. fig. 49, b), in which there are 

 observed, connective-tissue corpuscles with prolongations, 

 and minute nutritory ducts furnished with epithelium. The 

 connective-tissue is hyaline. At the point where 5 — 6 cells 

 join together, there is, sometimes, a somewhat broader 

 hyaline connective-tissue, in which, 2, large, round, nutritory 

 ducts are seen, clad with epithelium, traversing the 

 entire stem and appearing to form the true sarcosoma 

 or structural material of the colony (PI. XIX, fig. 49, c). 

 If we consider the entire Zoanthodem as consisting of a 

 stem from which the polyps spring, the concreted walls of 

 the polyp-cells will, then, correspond to the divisional 

 walls which form the chief ducts of the Alcyonoids in 

 general, but, as we know, there is always, in these, a 

 more or less extensive sarcosoma between the ducts, whilst 

 there is none found here. It is, consequently, this great 

 deficiency in sarcosoma which causes the entire Zoantho- 

 dem, when the polyps are fully extended, to be quite 

 transparent and very flexible. 



On the inner surface of the hyaline connective-tissue 

 of the polyp-cell, 8 fillet-formed prominences are seen 

 throughout the entire length; these are the septula issuing 

 from the polyp-body, and they extend right down to the 

 bottom of the cell (that of the prolonged gastral cavity) 

 (PI. XIX, fig. 49, d'). To the margins of 2 of these sep- 

 tula, the dorsal gastral filaments are attached. The sep- 

 tula are furnished with muscular fibres, so arranged, that 

 on the one side they form longitudinal, and on the other 

 side more-diagonally placed muscles. Both the muscular 

 layers, as well as, also, the entire inner surface of the 

 polyp-cells, are clad with an endothelium, formed of a layer 

 of very small, round, rather pellucid, cells containing a 

 nucleus and nucleolus. In a few sections it appeared as 

 if the entire inner surface had muscular fibres which 

 were much scattered, but which, upon the septula, collected 

 together into longitudinal and diagonal muscles, and it 

 may, perhaps, be that that is the true relation. Each 



