Anatomisk-histologisk Undersøgelse. 



Stammen, det vil sige de sammenvoxede Polypceller, 

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

 Lag polyædriske Celler, der 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 Eetodermceller sees hist og her pæreformige, 

 encellede Slimkjertler, lig dem. eler tidligere ere beskrevne, 

 samt en Mængde Spilder, Tab. XX, Fig. 1, a. Dette gjælder 

 dog knn 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, b, 

 hvori der iagttages Bindevævslegemer med Udløbere og fine 

 Ernæringskanaler. forsynede med Epithel; Bindevævet 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 Zoanthodemet som bestaaende 

 af en Stamme, hvorfra Polyperne udspringe, saa svare de 

 sammenvoxede Vægge af Poly])cellerne til Skillevæggene. 

 der danne Hovedkanalerne hos Alcyoniderne i Almindelig. 

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

 eller mindre udbredt Coenenchym imellem Kanalerne, 

 imedens her intet saadant 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 boieligt. 



Paa den indre Flade af Polypcellens hyaline Binde- 

 væv sees i hele Længden 8 listeformige Fremspring, sum 

 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 

 Gastralfilamenter fæstede. Septnla ere forsynede med 

 Mnskeltibre. som ere saaledes ordnede, at de paa den ene 

 Sid..' danne Længde- og paa den anden mere paaskraas 

 gaaende Muskler; begge Muskellag. ligesom hele den ind- 

 vendige Flade af Polypeellerne, 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 Skraainuskler, og det tør vel 

 hænde, at dette Forhold er det rette. Enhver Celle 

 strækker sig ned til Basaldelen, der danner dens Bund, 

 og imedens dm øverste Del er ganske afsluttet, saa er 



Anatomo-histological Exam i nation. 



Tlie stem. that is to say the concreted polyp cells, 

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

 Layers of polyhedricaJ cells measuring 0.006""", and con- 

 taining a somewhat eccentric nucleus with nucleolus, sur- 

 rounded by a pretty thin protoplasmic mass. Between 

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

 form, unicellular, mueous glands like those which have been 

 previously described, and also a niultitude of spicules 

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

 external walls of the polyp-cells; the inner wålls ar,' 

 concreted together and have no ectoderm (Pl. XIX. 

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

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

 2 cells) (Pl. XTX. rig. 49, a), that the layer is no thicker, 

 but even somewhat thinner, than the connective-tissue of 

 the miter wall (Pl. XIX. rig. 4'.». 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 ."> — (i 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 <>t the colony (Pl. XIX. rig. 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, hut. 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-eell, 8 tillet -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) 

 (Pl. XIX. fig. 49. dt. 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 otlier 

 side more-diagonally placed muscles. Both the muscular 

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

 polyp-cells. are clad witli an endothélium, formed of a laver 

 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 

 inay. perhaps. he that that is the true relation. Each 



