19 



vævsforlængelser, som sees bedst paa Tversnit, Tab. V, Fig. 

 ."). 6 a, fæster sig et Epithel, der bestaar af næsten runde, 

 store Celler, hvis Membran er tyml og vandklar, og hvis 

 store, runde, centralliggen.de Kjerne med sit runde Kjerne- 

 legeme er omgiven af fintkornet Protoplasma, Tab. V, Fig. 

 4, 5 b. I mange Celler sees Kjernen at være delt i mange 

 smaa, runde Legemer, som er den begyndende Spermatozoe- 

 dannelse, Tab. V, Fig. 6 b. Disse spermatogene Celler 

 danne flere Lag og udfykle en god Del af Genitalrørets 

 Linnen, i hvis Midte sees en stor Mængde Spermatozoer 

 med deres lange Haler, Tab. V, Fig. 3 b. 4 c. For 

 Størstedelen ligge Spermatozoerne i Bundter, ligesom sam- 

 menklistrede, og kunne forfølges hen til Cellerne. hvorfra 

 de ere udgaaede. Genitalrørets Afeg er betydelig fortykket 

 og forsynet med spindelformige Binde vævslegem er, Tab. V, 

 Fig. 4d. 



Jeg har havt Anledning til at undersøge Generations- 

 organet hos Antedon Eschrichti, petasus og prolixa, og har 

 for Testikelens Vedkommende ikke fundet noget væsentligt 

 forskjelligt fra, hvad jeg har angivet for Bathycrinus Car- 

 penteri. Hos dem alle udgaar der fra det indre Genital- 

 rørs Yæg Bindevævslister, paa hvilke de spermatogene Cel- 

 ler ere festede. Disse Lister synes ikke at forgrene sig, 

 saaledes som Tilfældet er hos Bathycrinus Carpenteri, men 

 ere noget bredere og staar mere regelmæssigt ud fra 

 Væggen, Tab. IV, Fig. 7, 8 a, og naa kanske noget hen- 

 gere ind i Genitah*ørets Luraen, Tab. IV, Fig. 7, 8. 

 Baade ved deres Regelmæssighed og ved deres Tykkelse 

 ser det ud paa Snitobjekter, som der fra Testikelens (Geni- 

 talrorets) indre Væg reiser sig en Mængde Pyramider til 

 Befestning for Cellerne. 



Crinoidernes Nervesystem er først opdaget af Professor 

 "W. Carpenter, der allerede i 1865 paaviste, at den Mantel, 

 der omslutter det femkamrede Organ, og hvorfra Forgre- 

 ninger udgaa, er det egentlige Nervesystem. Der hengik 

 jo adskillig Tid, inden dette blev fuldt ud anerkjendt; thi 

 der var flere betydningsfulde Forskere, som havde beskjæf- 

 tiget sig med Crinoidernes Anatomi, der bestred det. Men 

 nu synes al Tvivl at være hævet, idet P. H. Carpenter, 

 Jiekeli, Perrier, 0. Hamann, C. Vogt, Young og fl. ikke 

 alene have konstateret Rigtigheden af Prof. W. Carpenters 

 Iagttagelser, men ogsaa yderligere udvidet Undersøgelserne 

 i histologisk Retning og derved været istand til at opstille 

 et meget sammensat og temmelig høit udviklet Nervesystem. 



For Bathycrinus Carpenterfs Aædkommende afviger 

 Nervesystemet ikke i nogen væsentlig Grad fra de tidligere 

 undersøgte Crinoiders, og forsaavidt kan jeg henvise til de 

 seneste af Carpenter, Perrier og Hamann leverede udforlige 

 Beskrivelser over samme. 



Hamann inddeler Nervesystemet i et Dorsalnervesy- 

 stem, et Ventral- og et Ambulacralhervesystem i , og Perrier 

 tiltræder med god Grund denne Inddeling. 



1. c. pa 



63. 



tigs. 3. 4 a). Upon those connective-tissue prolongations, 

 which are best seen in transversal sections (Pl. V, figs. . r >. 

 6 a), an epithelium attaches itself, which consists of ahnost 

 round. large cells whose membrane is thin and pellucid. 

 and whose large, round. centrally situated nucleus with its 

 round curpuscle is surrounded liv finely granulated proto- 

 plasm (Pl. V, figs. 4, 5 b). In numerous cells the nucleus 

 is seen to be divided into many small, round bodies, which 

 are the rudimentary formation of spermatozoa (Pl. V, fig. 

 6 b). Those spermatogenous cells form several lavers, and 

 occupy a large part of the channel of the genital tube. in 

 whose middle a great quantity of spermatozoa with their 

 long caudal appendages are visible (Pl. V, figs. 3b, 4 c). 

 The spermatozoa lie for the greater part in bundles, as if 

 agglutinated, and may be ttaced up to the cells from 

 which they have issued. The wall of the genital tube is 

 considerably thickened, and is furnished with fusiform con- 

 nective-tissue bodies (Pl. V, fig. 4 d). 



I have had an opportunity of examining the reproduc- 

 tive organs in Antedon eschrichti, petasus and prolixa. and 

 have. in regard to the testicles. found nothing materially 

 different from what I have stated concerning Bathycrinus 

 Carpenteri. In all of them there issue, from the wall of 

 the inner genital tube, connective-tissue fillets to which the 

 spermatogenous cells are attached. These fillets do not 

 appear to ramify, as is the case in Bathycrinus Carpenteri, 

 but they are somewhat broader and stand more regularly 

 out from the wall (Pl. IV, figs. 7, 8 a), and they extend, 

 perhaps, somewhat farther into the channel of the genital 

 tube (Pl. IV. figs. 7, 8). Both by their regularity and 

 by their thickness, it appears, in sectional preparations, 

 as if from the inner wall of the testicle (the genital tube) 

 there arise a multitude of pyramids for the attachment of 

 the cells. 



The nervous system of the Crinoids was first discov- 

 ered by Professor W. Carpenter, who, already in 1865. 

 showed that the covering which enclosed the five-chambered 

 organ and from which the ramifications issue. was the re:tl 

 nervous system. A considerable time passed, to be sure. 

 before that was fully acknowledged, as there were several 

 renowned naturalists that had studied the anatomy of the 

 Crinoids who denied it. But now all doubt seems to have 

 disappeared, as P. H. Carpenter, Jiekeli. Perrier. 0. Hamann, 

 C. Vogt, Young and others, have not only confirmed the 

 correctness of Professor W. Carpenter's observations, but 

 have, still further extended the investigations in a histologi- 

 cal direction, and have thus been able to establish a 

 very complex and pretty highly developed nervous system. 



As far as regards Bathycrinus Carpenteri, the nervous 

 system does not differ in any material degree from the 

 previously investigated crinoids, and I may therefore refer 

 the reader to the latest detailed descriptions of the same 

 published by Carpenter, Perrier and Hamann. 



Hamann divides the nervous system into a dorsal ner- 

 vous system, a ventral, and an ambulacral nervous system \ 

 and Perrier, with good reason. adopts that system of division. 



page 63. 



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