12 



utvivlsomt. Den store, fuldt udviklede Stilk og den i 

 Forhold dertil saa yderst lille Krone hentydede allerede 

 derpaa, og naar man tillige saa hen til Kronens Dannelse, 

 at Eadialerne vare forholdsvis temmelig lange og smale, at 

 Basalerne vare sammen voxede til en fast Ring uden Spor 

 af Sømme, og at Armene vare kun lidet udviklede, saa 

 synes enhver Tvivl at maatte svinde. 



Sammenligner man dette Exemplar med et normalt 

 udviklet Individ af samme Størrelse, saa er Kronen paa 

 dette omkring 15""" hoi med Arme forsynede med Pinnuler, 

 Ambulacralfure og Tentakler. Der er vel heller ikke noget 

 væsentligt til Hinder for en saadan ny Kronedannelse ; th 1 

 Basalerne paa den gamle Stilk danner jo den nederste Del 

 af Calyx, som indeslutter det femkamrede Organ med sit 

 Centralnervesytem, og Centralkarret i Stilken, der fører 

 Nærings vædsken til det femkamrede Organ, vil jo forsyne 

 Nydannelsen med de fornødne Næringsmidler. Iblandt 

 Echinodermerne er det især for Asteridernes Vedkommende 

 at flere Forskere ere af den Mening, at en løsreven Arm er 

 istan d til at producere en ny Skive, og jeg er ikke i Tvivl 

 om, at dette forholder sig saa. Jeg har iagttaget paa 

 Asterias Mlilleri, at den afkastede dels 1. dels 2 Arme, og 

 at der fra den løsrevne Arm, som levede 3 — 4 Dger efter 

 Løsrivelsen, begyndte at udskyde en Knop, der antog en 

 atlang Form, og som var Anlægget til den vordende Skive. 

 I Knoppens Hulhed var den begyndende Mave. en For- 

 længelse af det i Armen værende Maveappendix, der korre- 

 sponderede med Hulheden. Jeg -kunde ikke holde den 

 Løsrevne Arm længere i Live, særegne Omstændigheder bi- 

 drog dertil, saa en fuldstændig Skivedannelse ikke kom 

 istand. Den ny Kronedannelse paa den gamle Stilk hos 

 Bathyerinus Carpenteri staar saaledes ikke som noget isoleret 

 Phænomen men tinder sit Tilknytningspunkt i den omtalte 

 Skivedannelse hos enkelte Asterider. Dersom jeg kun 

 havde det ene Exemplar at støtte mig til med Hensyn til 

 den nye Kronedannelse, saa kunde man tænke sig. at man 

 havde med en særegen, isoleret Abnormitet, men saa er 

 ikke Tilfældet; thi paa to andre Stationer fandtes lignende 

 Exemplarer, kun lidt forskjellig i Størrelse og Udvikling. 



Paa Station 295, lllU Favne, Temperatur —1.2 C, 

 opfangedes med Travlen i tyndt Ler flere Exemplarer af 

 Bathyerinus Carpenteri, hvoraf de fleste vare uden Krone, 

 men alle Stilke vare forsynede med Basaler; iblandt disse 

 var der en, som frembød en ny Kronedannelse. Stilken 

 var 122""" hoi, Roden 35""" lang og Kronen o..v"'" hoi, Tab. 

 Ill, Fig, 3. Stilken havde Udseende af at være temmelig 

 gammel; paa flere Steder af den- havde der fæstet sig sniaa 

 Alcyonarie-Kolonier, Tab. III, Fig. 3 a, hvoraf den ene. 

 den største nemlig, visselig daterer sig fra en ældre Tid. 

 Leddene vare meget store og lidet bøielige, saaledes som 

 Tilfældet er hos gamle Individer, og Basalerne vare fuld- 



damaging them, be separated from each other, On the 

 arms, it is true, the ambulaeral groove was seen, but no 

 tentacles. That a new crown was in course of formation 

 in that specimen seems to be indubitable. The large, 

 fully developed stalk with the relatively so small crown 

 already indicated that, and when, besides, we regard the 

 formation of the crown. that the radials were relatively 

 pretty long and narrow. that the basals were concreted 

 into a finn ring without trace of seams, and that the arms 

 were only little developed. it appears as if every doubt 

 must disappear. 



If we compare that specimen with a normally devel- 

 oped individual of the same size, the crown upon the latter 

 is about 15""" in height, with arms furnished with pinnules, 

 ambulaeral grooves and tentacles. Neither is there, prob- 

 ably, any essential hindrance to the formation of such a 

 new crown, because the basals on the old stalk form. of 

 course. the lowest part of the calyx, which encloses the 

 five-ehambered organ with its central nervous system, and 

 the central vessel in the stalk which leads the nutritory fluid 

 to the five-chambered organ will, of course, supply the new 

 formation with the necessary nutriment. Among the 

 Eehinoderms it is espeeially in regard to the Asterids that 

 several naturalists hold the opinion that a detached arm 

 is able to produce a new disc. and I entertain no doubt 

 that it is so. In Asterias Miilleri 1 have observed that 

 it threw off, partly 1. partly 2 arms. and that on the 

 detached arm. which survived for 3 — 4 weeks after the 

 detachment, a bud began to grow. which assumed an oblong 

 form and was the rudiment of the future disc. In the 

 cavity of the bud was the rudimentary stomach, a prolon- 

 gation of the stomach-appendix situated in the arm. which 

 corresponded with the cavity. I could not maintain 

 the detached arm longer alive, special circumstances con- 

 tributed to that, so that a complete formation of disc did 

 not take place. The new formation of crown on the old 

 stalk of Bathyerinus carpenteri does not, therefore, stand 

 as an isolated phenomen, but tinds its connecting point 

 of resemblance in the discal formation spoken of jn a few 

 Asterids. If I only had had the one specimen upon 

 which to base my opinion in regard to the formation of 

 the new crown, then it might be supposed that one had 

 to do with a special, isolated abnormity; but that is not 

 the case, as at two other stations similar specimens were 

 found. differing only a little in size and development. 



At station 295, in 11 KJ fathoms. temperature — 1/2 C, 

 several specimens of Bathyerinus carpenteri were secured 

 by the trawl in thin clay. of which the greater number 

 were without crown. but 'all the stalks were furnished with 

 basals; among these was one that presented a new formation 

 of crown. The stalk was 122""" in height, the root 35"" n 

 long. and the crown 3.5"™ high (Pl. III, fig. 3). The stalk 

 had the appearance of being pretty old: on several portions 

 of it colonies of Alcyonaria had attached themselves (Pl. 

 III, fig. 3 a), of which one, the oldest namely, evidently 

 dated from an older period. The joints were very large 

 and little flexible, like what is the case in old individuals, 



