20 KJELLMAN, THE ALG^ OF THE ARCTIC SEA. 



Probable causes of the peculiarities in the general character of 



the arctic Flora. 



It has been shown, in the preceding exposition, that the generalcharacter of the marine 

 Flora varies in different parts of the Arctic Sea, and that this Flora, considered as a 

 whole, presents several remarkable peculiarities of physiognomy, as compared with that 

 of other parts of the ocean. That .these peculiarities are essentially, though not ex- 

 clusively, caused by certain cooperating physical circumstances peculiar to the Arctic 

 Sea, I regard a's a settled truth, although it is impossible at present, on account of 

 our imperfect knowledge of the biology of the marine algae, to state decidedly which 

 these circumstances are, and in what direction and with what power they act. I think, 

 however, that the chief causes are the state of the ice, the configuration of the coast, 

 the tide, the nature of the bottom, the salinity of the water, the temperature of the 

 sea, the temperature of the air, and the want of light. 



The state of the ice. The influence of the ice on the vegetation of the Arctic Sea 

 is decidedly unfavourable, the ice either l:o) making the growth of algfe impossible, 

 or 2:o) making the period of vegetation too short for the algae to reach their full de- 

 velopment, or 3:o) tearing off alg£e in development, or 4:o) making the bottom unfit for 

 the prosperous growth of algae. The two first-mentioned effects are caused by the 

 fixed unbroken land-ice, the two latter by broken-up ice-masses being carried along 

 the shores by waves and currents. In the greatest part of the Arctic Sea there is 

 formed during the winter a girdle of thick, coarse ice, which nearest the shores is pressed 

 close to the bottom. At certain places this land-ice remains throughout the year, at 

 others it is indeed destroyed, but usually only late in the year. I have already men- 

 tioned that the ice-foot was found remaining everywhere along the shore at Cape 

 Chelyuskin during our stay there at the end of August, and I may add here, that this 

 ice was so strong and thick, that the shore could not probably get free from ice in 

 the course of that summer. In 1875 the interior of Karraakul Bay in south Novaya 

 Zemlya was still covered with unbroken masses of iCe in the last days of June, and 

 even in the middle of July this was in great part the case with the sound between 

 north and south Novaya Zemlya ^). It is clear that no algte can develop as long as 

 this fixed land-ice remains, and it seems to me highly probable that when this ice, as 

 is often the case, is not dissolved or destroyed ere late in summer, — consequently 

 only a short time before new ice is formed again — the time left a marine vege- 

 tation to spring up in such regions is insufficient for some algae to attain their full 



') Cp. NoRDENSKioLD, Proven p. 14 and 22, and Kjellman, Algenv. Muvra. Meer p. 59. 



