KUNGL. sv. VET. AKADEMIENS BANDLINGAE. BAND 47. \d I. 7 



In my conviction, tliis fact cannot be explained otherwise bhan tbal bhe latter speoit 

 organised exclusively for a life under pure arctic conditions, and fchat when ii is carried away 

 towards the warmer southern zones, it is going to destruction, whilc Calanus finmarchicus is 

 endowed with a capacity of existing almost as a cosmopolitan, that is fco say, it must !><• 

 provided with such qualities, that it is able to stånd very different conditions and con i 

 quently to recruit the pelagic fauna in the oceans far from the supposed »native place» in the 

 arctic regions. 1 



For my part, I must confers that I long ago entertained views differenl from those of 

 other investigators. Thus, e. g., I am convinced that Calanus finmarchicus, supposing it really 

 has this very wide distribution, has its cradle in several or many centres not only in the northern 

 and arctic seas, hut prohably also in other parts of the oceans. Because, like other animals of 

 the Holoplankton it is bom in the open sea and is adapted for a life there, independent of the 

 shores and the sea-bottom. According to the views that I have enunciated here, all true animals 

 of the Holoplankton with a wide distribution have many cradles in the oceans — never or rarely a single 

 one. If, for instance, Calanus helgolandicus is met with at Heligoland, in the Mediterranean, in 

 the Black Sea, in several places of the Atlantic and also off New Zeaiand, is it reasonable to 

 assume off hand that its breeding-place has been the coast of Heligoland alone, and that it should 

 have been drifted by currents from this »centrum» all över the world? At least I myself cannot 

 admit such views. Therefor I think that those scientists are wrong which have come to the 

 conclusion that they can determine the direction of the sea-currents in the main by the occurrence of 

 h oloplankton-an imals. 



After this short and superficial introductory discourse of the distribution and 

 life of the holoplankton-animals, I return to the shore and shallow-water fauna, the 

 real subject of my present paper. 



The shallow-water fauna comprehends all such animals which inhabit the littoral 

 region down to a depht of about 400 m. In conformity with the German investigator 

 Pfeffer, 2 I consider it to be »the mother of all faunas». For the shallow-water 

 ground offers conditions for existence much more than any other. The sun-beams 

 penetrate the water layers right down to the bottom. The vegetation is lnxuriant 

 and abundant in forms of different qualities. The schallow- water is very richly 

 supplied with oxygen, is kept in permanent motion and is, besides, subjected to 

 varying temperature and salinity. Finally, the bottom is highly difform, often rocky 

 and overgrown with forests of algse. To sum up, all the different conditions have 

 in the course of time raised a fauna of infinite variegation. 



1 This aceount is based on the views of Giesbrecht, Brady and Aurivillius. However, Särs (An account 

 of the Crustacea of Norway — Bergen 1903) entertains a different opinion with regard to the distribution of 

 Calanus finmarchicus. He says: »It has, however, been confounded by most authors with the succeeding nearly- 

 allied species [Calanus helgolandicus (Claus)]. . . Of all the raarine Calanids of Norway, this form is by far the 

 most common, occurring often in enormous shoals, and thus sometimes giving the sea a conspicuously reddish 

 hue. It is found every where in the open sea. more frequently at the very surface, though at times it may also 

 descend to greater depths. . . Off the Norwegian coasts I have met with it from Wardö to Jaederen (Tananger), 

 but farther south it seems to be superseded by the succeeding species (Calanus helgolandicus). 



2 Versuch iiber die erdgeschichtliche Entwicklung der jetzigen Verbreitungsverhältnisse unserer Tierwelt. 

 Hamburg 1891. [Théel, Om »bipolaritet» i hafsorganismemas utbredning. Ymer 1900.] 



