22 



ligeledes løbe ved Siden af Pinnulens Vandkar, Tab. II, 

 Fig. 4 d. De ventrale Nervegrene lios Bathycrinus Oar- 

 penteri ere ligesaa tykke om ikke tykkere, end den dorsale 

 Gren. men have langt færre Ganglier end denne. 



Fra Armens ventrale Nervegrene udgaa en stor 

 Mængde Grene, hvoraf flere korrespondere med Grene fra 

 Dorsalnerven og desforuden afgive Grene til Hud og Ten- 

 takler. Da Pinnulerne egentlig ere Fortsættelser af Armene, 

 saa faa de ogsaa sine Nervegrene fra disse. Fra Nerve- 

 grenen i Tentaklerne synes fine Udlobere at strække sig 

 ind i Papillernes Basaldel. Hver Papille bar paa sin yderste 

 Ende 4 haarfine Børster, hvoraf den Midterste er den 

 længste og synes at være en Fortsættelse af den af Perrier 

 omtalte Centralstræng. Jickeli er den Forste, som har 

 undersøgt disse Papiller mere nøiagtigt og slutter sig med 

 Hensyn til deres physiologiske Betydning til flere Forskere, 

 idet han antager dem for sensitive Organer. Hos Hamann 1 

 ere lignende Papiller nærmere beskrevne og afbildede, 

 hvortil henvises. 



Endelig er der endnu et 3die Nervesystem hos Ba- 

 thycrinus Carpenteri, som svarer nogenlunde til det af Pro- 

 fessor Ludvig forst paaviste Ambulacralnervesystem. Det 

 af ham angivne, subepitheliale Plexus skulde danne en pen- 

 tagonal Svælgring, der laa under Svælgepithelet og sendte 

 Grene ud til Ambulaeralfuren. Jickeli og Hamann have 

 ikke fundet nogen saadan Svælgring og mene, at Ambula- 

 cralnerverne efter at have passeret Mundskiven udbreder 

 sig paa Spiserøret for at fortsættes paa Tarmen uden at 

 danne nogen Svælgring ; ligesaa paaviser Hamann, at disse 

 Nerver ikke ere subepitheliale men vel epitheliale. Hos 

 Bathycrinus Carpenteri ere disse Ambulacralnerver meget 

 tydelige — der ere de aabenbart epitheliale — , men om 

 de udgaa fra en Svælgring eller de simpelthen komme fra 

 Armene og udbrede sig i Svælgvæggen, kan jeg ikke afgjøre; 

 paa et Snit saa det virkelig ud, som om der var en epi- 

 thelial Svælgring, men paa mange andre fandtes den ikke, 

 saa jeg er tilbøielig til at antage, at en saadan Nervering 

 ikke findes hos Bathycrinus Carpenteri. 



Farven. Den er helt igjennem smuk straagul, kun 

 Rodpartiet er lidt mørkere end den øvrige Del af Stilken. 

 Kronen er kanske lidt blegere; men naar Kjønsorganerne 

 ere fuldt udviklede med Kjonsprodukter har Pinnulerne en 

 meget mørkere Farve. Spiritus forandrer Farven yderst 

 lidet. 



1 1. c. -1. 



arm has thus 2 ventral and 1 dorsal nerve-brancb. The 

 ven tral nervous branches of the arm give off 2 branches to 

 each pinnule, which also run at the side of the water- 

 vessel of the pinnule (Pl. II, fig. 4 d). The ventral nervous 

 branches in Bathycrinus Carpenteri are quite as thick, if 

 not thicker than the dorsal branch, but have far fewer 

 ganglia than it. 



From the ventral nervous branches of the arm there 

 issue a great multitude of branches. of which sevéYal cor- 

 respond with branches from the dorsal nerve, and give off, 

 besides, branches to the integument and the tentacles. As 

 the pinnules are really continuations of the arms, they also 

 obtain from them their nervous branches. From the ner- 

 vous branch in the tentacles, delieate prolongations appear 

 to stretch theinselves into the basal part of the papillæ. 

 Each jtapilla has 4 bristles, as tine as a hair, seated on 

 its outermost extremity, of which the middle one is the 

 longest and appears to be a continuation of the central 

 cord mentioned by Perrier. Jickeli is the first who lias 

 investigated those papillæ more exactly, and in regard to 

 their physiological importaiice he agrees with several in- 

 vestigators, as he assumes them to be sensitory organs. 

 Similar papillæ are f uliv described and illustrated by 

 Hamann 1 , to whose works I therefore refer. 



Finally, there is yet a 3rd nervous system in Bathy- 

 crinus Carpenteri. which corresponds in some degree with the 

 ambulacral nervous system first shown by Professor Ludvig. 

 Tlie sub-epithelial plexus mentioned by him was stated to 

 form a pentagonal æsophageal ring that lay below the epi- 

 thelium of the æsophagns, and sent out branches to the 

 ambulacral groove. Jickeli and Hamann have not discov- 

 ered any such æsophageal ring, and believe that the am- 

 bulacral nerves, after having passed the oral disc, distribute 

 themselves on the gullet-tube for continuation on the intes- 

 tine, without forming any æsophageal ring; while Hamann 

 also shows that those nerves are not sub-epithelial ones, 

 but really epithelial. In Bathycrinus Carpenteri those am- 

 bulacral nerves are very distinct — there they are evidently 

 epithelial — but whether they issue from an æsophageal 

 ring. or simply come from the arms and distribute them- 

 selves in the wall of the æsophagus, lam unable to decide; 

 in one section it really appeared as if there were an epithelial 

 æsophageal ring, but in many others it was not found, so 

 that I am disposed to assume that such a nerve-ring does 

 not exist in Bathycrinus Carpenteri. 



The Colour: It is everywhere a beautiful straw- 

 yellow, the root portion, only, being a little darker than the 

 rest of the stalk. The crown is perhaps a little paler in 

 colour; but wben the sexual organs are fully developed 

 with sexual products the pinnules have a much darker 

 colour. The colour changes extremely little in alcohol. 



c. S4. 



