26 



Anatomisk-histologisk Undersøgelse. 



Hele Zoanthodemet har et Ectoderm, dannet af flere 

 Lag temmelig store, klare, polyædriske Celler, forsynede med 

 en rund, lidt excentrisk liggende Kjerne samt Kjemelegeme. 

 I de indre Lag sees imellom Ectodermcellerne mange æg- 

 formede, encellede Slimkjertler, der dels ere tomme og 

 have Udseende af Vacuoler. dels har en centralliggende, 

 lidt aflang Kjerne omgiven af Protoplasm åkorn ; paa en- 

 kelte af disse Slimkjertler kunne iagttages en Udførsels- 

 gang, der munder ud paa Overfladen. Foruden disse 

 Slimkjertler ere en stor Mængde tætliggende Spikler ind- 

 leirede saavel i Stammens som Polypernes Ectoderm. 

 Bindevævslaget er hyalint, temmelig smalt, og fra dets indre 

 Væg udgaa i Stammen og Grenene de Forlængelser, der 

 danne Kanalernes Skillevægge, og som i Polypkroppen 

 danne Septa; hverken i disse eller i Stammens Skillevægge 

 tindes Kalk. Den indvendige Flade af Bindevævslaget er 

 overalt beklædt med et Endothel, bestaaende af et Lag 

 runde Celler, der ere temmelig klare, have en rund 

 Kjerne med Kjemelegeme og et yderst fintkornet, gjennem- 

 sigtigt Indhold. Svælget er cylindrisk, langstrakt og har 

 8 Længderækker Spikler, Fig. 56, A, og paa dets indre 

 Bngflade en oval Svælgrende, der er beklædt med lange 

 Pidskeceller. 



Paa Basaldelen ligge Spiklerne noget kompakte paa 

 hverandre, og de hyppigste Former, hvorunder de optræde, 

 ere Dobbeltstjerner og Klubber; sammensatte Stjerner ere 

 meget sjeldnere og Firlinger endnu sjeldnere. Dobbelt- 

 stjernerne ere mere eller mindre udviklede ; de fuldkomment 

 udviklede have et temmelig langt Midtbelte, der dels er 

 ganske nøgent, dels besat med Papiller. Straalerne i 

 begge Ender ere meget brede med tandede Rande, og stun- 

 dom ender hver Straale i en liden Stjerne: de ere fra 

 0.120— 0.160""" lange og fra 0.056—0.088""» brede i 

 Enderne med Midtpartiet fra 0.024— 0.036™" bredt, Fig. 

 57. 58. 59. 60. 61. 62. Klubberne ere dels sparsomt be- 

 satte med Takker eller Blade, der staa langt fra hver- 

 andre, dels ere de meget rigt forsynede med brede, i 

 Randen takkede Blade; de første, kan hænde, ere mindre 

 udviklede; de ere fra 0.128—0.172""" lange og fra 0.056— 

 0.068""" brede foroven, Fig. 63. 64; de sidste nærme sig 

 noget de sammensatte Stjerner, ere 0.188""" lange og fra 

 0.104""" brede foroven, Fig. 65. Firlingerne ere i Kors- 

 og Rosetform. begge rigt udsmykkede med Blade og 

 Papiller og fra (i. 108 — 0.144""" lange og 0.120""" brede. 

 Fig. 66. 67. 



Paa Stammen ere de sammensatte Stjerner alminde- 

 ligst. sjeldnere Klubber og Dobbeltstjerner. De sammen- 



Anatomo-histological Examination. 



The entire Zoanthodem has an ectoderm. formed of 

 several layers of pretty large translucent polyhedrical cells, 

 furnished with a round. somewhat eccentrically placed, nuc- 

 leus and nucleus-corpuscle. In the inner layers there 

 are seen, between the ectoderm-cells, many oviform. uni- 

 cellular mucous glands which are, partly, empty, and have 

 the appearance of vacuoli, or they have. partly, a centrally 

 placed, somewhat oblong, nucleus surrounded by protoplas- 

 mic grannules. In a few of these mucous glands, an 

 excretory duct which discliarges upon the exterior surface 

 may be observed. Besides these mucous glands, there 

 are a great many closely placed spicules entrenched, both, 

 in the stem. and in the ectoderm of the polyps. The 

 connective tissue is hyaline [and rather narrow. and from its 

 inner wall issue — in the stem and the branches — the 

 prolongations which form the divisional walls of the ducts, 

 and which. in the polyp-body, form septa. Neither in 

 these. nor in the divisional walls of the stem, is calcium 

 found. The interior surfaGe of the connective-tissue layer 

 is, everywhere. clad with an endothelium, consisting of a 

 layer of cylinder-cells which are pretty translucent, and 

 which contain a round nucleus with nucleus-corpuscle, and 

 an extremely miimte. grannular transparent protoplasm. The 

 gullet is cylindrical and elongate, and has 8 longitudinal 

 series of spicules (fig. 56. A) and on its inner ventral sur- 

 face it has an oval gullet-passage clad with long flagelli- 

 form cells. 



In the basal part, the spicules are placed. somewhat 

 compactly, upon eacli other, and the most frequent forms 

 in which they occur are the bistellates and clavates; 

 complex stellates are much less frequent, and quadruplets are 

 still more rare. The bistellates are more or less developed ; 

 the completely developed ones have a pretty lonii middle stripe, 

 partly. quite hare. and partly. beset with papillæ. The rays 

 are, at both extremities, very broad, and have dentated mar- 

 gins, and sometimes each rav terminatés in a small star ; they 

 measure from 0.120—0.160""" in length, and from 0.056 

 — 0.088'"'" in breadth at the extremities, and the middle 

 part measures from 0.024 — 0.036""" in breadth (figs. 57. 58. 

 59. litt. 61. 62. The clavates are. partly, sparingly beset with 

 spikes, or leaves, placed far apart from each other, or 

 they are, partly. very richly furnished with broad leaves 

 dentated in the margins. The first named are perhaps only 

 partially developed; they measure from 0.128 — 0.172""" in 

 length, and from 0.056 — 0.068""" in breadth above (figs. 

 63. 64). The last named approacli, in form, somewhat, 

 to the complex stellates; they measure U.188""" in length, 

 and 0.104""" in breadth above (fig. 65). The quadruplets 

 appear as cruciforms and rosetti-forms, both. richly adorned 

 with leaves and papillæ; they measure from 0.108 — 0.144""" 

 in length, and 0.120""" in breadth (fig. 66. 67). 



In the stem. the complex stellates are the most 

 frequent spicular form; more rarely do clavates and bistel- 



