III 



ved dettes Hulhed deles efter Længden paa en saadan 

 Maade, at Svælgrenden danner det egentlige Svælg (Øso- 

 phagus), imeclens den øvrige Del kan betragtes som Tarm, 

 se Side 102. 



Svælget er rigt forsynet med encellede Slimkjertler, 

 der forøvrigt findes i stor Mængde paa Polypkroppens ud- 

 vendige Flade hos alle de undersøgte Arter. 



Der har været sagt. at Alcyoniderne fremstille et 

 Ideal for den Kommunisme, hvor ingen Arbeidsdeling 

 finder Sted; men jeg tror ikke, dette forholder sig ganske saa. 

 Hos flere Arter af Slægten Nephthya har jeg fundet en 

 virkelig Arbeidsdeling, idet flere Polyper i Kolonien staa 

 udelukkende i Formerelsens Tjeneste. Saasnart Befrugt- 

 ningen er foregaaet, bøies Tentaklerne ind mod Munden, 

 der lukkes af en seig Slim, og Svælgrøret omdannes til en 

 Uterus, hvori Udviklingen foregaar; i denne Svangerskabs- 

 periode ernæres de befrugtede Polyper af andre i Kolo- 

 nien, se Side 82. 



Det er ogsaa hos Slægten Nephthya, jeg har kunnet 

 anstille nogle Iagttagelser over Udviklingen og derved for 

 en Del konstatere Kowalevsky's & Marion's Undersøgelser 

 over Udviklingen af Sympodium coralloides samt af Clavu- 

 laria crassa og petricola. 



Bergen, i Juni 1886. 



D. C Danielssen. 



by which its channel is longitudinally divided, in such a 

 manner that, the gullet-groove forms the real gullet 

 (oesophagus) whilst the remaining part may be regarded 

 as an intestine, vide pag. 102. 



The gullet is richly supplied with unicellular mucous 

 glands, which, also, are found in great abundance on the 

 external surface of the polyp, in all the species examined. 



It has been said that the Alcyonoids furnish an 

 ideal of Communism, where no division of labour takes 

 place, but I do not think this is quite the case. In the 

 genus Nephthya I have, in several species, found a genuine 

 division of labour, inasmuch that, several polyps of the 

 colony stand exclusively in the reproductive service. As 

 soon as the fructification has taken place the tentacles 

 become curved in towards the oral aperture, which becomes 

 closed by a viscid mucous. The gullet-tube becomes trans- 

 formed into a uterus Avhere the development proceeds; 

 during this gravid period the fructified polyps are nourished 

 by others of the colony, vide pag. 82. 



It is, therefore, in the genus Nephthya that I have 

 been able to make a few observations upon the develop- 

 ment and, thereby, to a certain extent, confirm Kowa- 

 lewskys and Marions observations on the development of 

 Sympodium coralloides and of Clavularia crassa et petricola. 



Bero-en, June 1886. 



D. C. Danielssen. 



