KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 36. N:(J 8. 5 



can be carried in the oceans. I vill take for exaniples two of the most heavy species, 

 Paralia sulcata and Åulacodiscus argus. The former was found last February scattered 

 at the surface över the whole North Sea. The very compact Aulacodisciis an/us was 

 once found in a saiuple collected at the surface at about 40° N. 17" W. or raidway between 

 Portugal and the Azores, thus about seven degrees from the nearest coast. 



I will next consider the distances to whicli true neritic diatoms can drift. 1 will 

 take tAvo forms, about which Mr. Gran certainly will agree with me that they are true 

 neritic forms, viz. Stephanopyxis turris and Eucampia zodiacus. Both occurred in the 

 spring of 1898 at about 48°N. 33°W., thus midway between the Azores, the European 

 coast bank and the NeAvfoundland banks, ten degrees from the Azores. 



For a better clearing up the question I will now make use of Mr. Gean's own 

 observations. In the above quoted latest paper of Mr. Gran's (p. 29) he mentions that 

 Chcetoceros cinctus occurred as far north as 64° and that it probably derived from Scot- 

 land. It must then have drifted 5 to 6 degrees. The same diatom was found at 64° N. 

 7° W. and Mr. Gran finds no difficulty in declaring that it must have come from Iceland, 

 i. e. had drifted about seven degrees. Mr. Gran admits thus that the pelagic diatoms 

 may drift in the oceans for considerable distances from their birthplaces. 



How does that agree with Mr. Gran's statement »dass die Diatomeen nur da auf- 

 treten können, wo Dauersporen auf dem Meeresboden in nicht zu grossen Tiefe vorhan- 

 den sind»? (p. 154). 



How utterly devoid of any real foundation such a statement is can be easily de- 

 monstrated. There occur, usually in the spring between Shetland, Scotland and Norway, 

 large masses of Chcetoceros deciinens, of which species nobody has hitherto found a single 

 resting spore, thus drifting above depths of 100 to 200 nietres. The same species was 

 met with, also in large masses, by the Nathorst expedition in 1899 at 66° — 67° N. 2° — 3° 

 W., thus in the deepest part of the northern Atlantic. 



There exists another kind of plankton-organisms which from Mr. Gran's point of 

 view could be termed »foreigners», a name which I suppose will cover what Gran calls 

 »nicht als in unserem Gebiete einheimisch». Such a form is, according to Mr. Gran, 

 Corethron hystrix, which I have found at Spitsbergen, »wohin sie ohne Zweifel mit dem 

 Strome getrieben sein muss» (Gran). This form »kommt aber Avahrscheinlich jeden Som- 

 mer von Siiden durch die Färöer-Shetland Rinne» (Gran). If I understand Mr. Gran 

 right, he admits that the species in question drifts from 60° to 76° N., thus about sixteen 

 degrees. If Mr. Gran admits such a long drift to a "foreigner» it seems really stränge 

 that he will not allow a »native» as inuch liberty. 



Plankton in fjords. »Relics». 



I have admitted above that resting spores of diatoms possibly may settle on the 

 bottom of sheltered basins, but that cannot help Mr. Gran's hypothesis. According to 

 Gran's own researches in the Nordland, the plankton of the fjords comes from without. 

 In his paper »Hydrographic-biological studies of the north Atlantic Ocean» (Kristiania 

 1899) he says on p. 23 that the water in the fjords becomes» dislodged, partly by in- 



