Oct. 30, 1884] 



NA TURE 



639 



drift-ice masses grind the upper shore-belt to such an 

 extent that every vestige of vegetation is decimated, if not 

 entirely destroyed. The tide contributes also greatly to 

 increase the disturbing influences of the ice, as by this 

 phenomenon the area of shore exposed to the action of 

 the ice becomes greatly increased, and by the circum- 

 stance that the ice-masses are thereby kept in constant 

 motion. Not even in the winter are the ice- masses 

 at rest along the shore. During the wintering of the 

 Swedish expedition at Spitzbergen at the northernmost 

 promontory of that island the sea outside the station, 

 Mossel Bay, was covered with hard, coarse ice, some 

 twenty miles in breadth. Still throughout the wintering 

 a grating sound was heard from the ice, caused by the 

 rubbing of the ice-floes and icebergs against each other as 

 they moved backwards and forwards, or rose and fell. That 

 a similar action would greatly affect the bottom of the 

 sea is quite evident, particularly as most of the shores of 

 the Arctic C cean are void of the protection afforded by 

 islands and fjords. The latter contribute to increase the 

 detrimental effect of the ice on the alga? flora. On an 

 open coast the action of the ice is, of course, more violent 

 than where it is protected by islands. For this reason 

 the upper shore-belt is nearly everywhere in the Arctic 

 Ocean void of algae where there are no protecting islands, 

 as, for instance, on the shore of North- Western Spitz- 

 bergen, on a few places at Novaya Zemlya, and particu- 

 larly at the west coast of Greenland. 



Another circumstance which greatly contributes to the 

 poorness of the algae flora in several parts of the Arctic 

 seas north of Asia is the brackishness of the water, caused 

 by the great Siberian rivers. The water of the surface 

 here consists of two parts river-water and one part sea- 

 water, a condition which is very detrimental to the 

 development of algas. 



The total absence of light in certain parts of the Arctic 

 regions during a very great part of the year also arrests 

 the growth of certain alga; which love the light. The 

 scarcity of green algae is, no doubt, due to this circum- 

 stance. 



It is natural to assume that the temperature of the 

 Arctic seas is low, but it is really lower than is generally 

 believed. Thus, during the warmest part of the year, in 

 the month of July, the mean surface temperature is from 

 + 'ii C. in the American Arctic Sea to + 3 c '3and 4°'33 

 in the sea around Spitzbergen and the Murman coast, 

 and it decreases greatly with the depth. At the depths at 

 which the algas flora is richest, it never rises above o° C. 

 That many species of algas are excluded from the Arctic 

 seas by this low temperature is evident. It is, indeed, to 

 be wondered at that there are algas in these icy waters at 

 all ; but that there are really many I will presently show. 



From what I have thus said, it appears that the algas- 

 covered spots in the Arctic seas are, so to speak, oases in 

 the great Polar water desert. Let us now examine the 

 conditions of the flora in these oases. Most of them have 

 but a poor and sparse vegetation. This is particularly 

 the case in the Siberian seas and the eastern part of the 

 Kara Sea, and, to some extent, in the western part of the 

 Kara Sea, the eastern part of the Murman Sea, the 

 Spitzbergen Sea (the sea to the east of Spitzbergen), and 

 the Greenland Sea (the sea between Greenland and Spitz- 

 bergen). Even where the quantity of alga; is greatest 

 within this area, it is much less than in the richest parts 

 of the Atlantic Ocean. In the western part of the Murman 

 Sea and the White Sea the vegetation is not so poor (ac- 

 cording to Chr. Gobi, "DieAlgen flora des Weisser. Meeres 

 und der demselben zunachst liegenden Theile des nord- 

 lichen Eismeeres," 1878). It is richest in Baffin's Bay, 

 on the uest coast of Greenland. The greatest authority on 

 the natural history of Greenland says on this point : "Just 

 outside the coast of Greenland the sea-bottom is covered 

 with a forest of giant algas, with leaves from 12 to 16 feet 

 in length and half a foot in width, besides which the 



stones are everywhere covered with coral-like layers (coral 

 algas)." The algas flora in this spot is, therefore, copious, 

 and is far in advance of those in other parts of the Arctic 

 Ocean. 



I have already said that the bottom of the Arctic Sea may 

 be divided botanically into three belts, viz. the upper shore, 

 the lower shore, and the deep-sea belt. Of these the first- 

 named is the poorest, the algas oases here being few and 

 limited, thevegetationpoorin individuals, and the algasvery 

 small. The west coast of Greenland, with its fjords and 

 islands, alone forms an exception in this respect. The upper 

 belt here often produces brown algas of considerable size 

 [Fiicacece), while even green and red are not wanting. 

 The deep-sea belt is, like the upper one, poor in species 

 and individuals. During the Swedish Arctic expeditions 

 only six species have been discovered in this belt, and 

 all of these lived at a considerable depth, one (Ptilota 

 tpeitinata, Gunn.) even at a depth of 270 metres. The 

 principal flora of the Arctic Sea belongs, however, to the 

 lower shore-belt. This belt everywhere possesses the largest 

 and the greatest number and variety of algas. Its charac- 

 teristic forms are two, viz leaf-weed algas {Laminaru « j 

 and coral algas (Coralltnacea). They cover large areas 

 of the bottom, and appear in close masses rich in indi- 

 viduals, which attain a gre;.t size. The leaf-weed alga; 

 make the greatest impression ; they derive their name 

 from the circumstance that they carry a large leaf at the 

 top, which is shed and renewed annually. All species 

 belonging to this family are large algas, some of them 

 attaining a length of 4 metres, and the top leaf a width 

 of 1 metre. They are the trees of the sea, and resemble 

 those on land by growing together in forests. These are 

 the algas which in the Arctic Ocean attain the greatest 

 size and cover the largest area, and so greatly contribute 

 to the general habitus of the flora of this ocean that one 

 mi.ht justly call it the " Ocean of the L;.minarieas." 



Next to the Laminarieas the Corallinaceas are the most 

 important. These algas form one of the wonders of the 

 terrestrial flora. Any one who thus sees them for the first 

 time would think that they were real corals or some kind 

 of stone. They are — as they appear in the Arctic seas — 

 perfectly hard, being impregnated with chalk, and have a 

 peculiar soft rosy or grayish-red colour. In form they 

 vary between the laminated and the bushy. Often, too, 

 they appear as detached ballss which have on their surface 

 shorter or longer branch-like projections. These balls may 

 attain a diameter of 20 centimetres, as, for instance, in 

 Lithothamnion glaciate (Kjellm.), and appear in certain 

 places in the Arctic seas in enormous quantities. On the 

 shores of Spitzbergen and Novaya Zemlya, for instance, 

 the bottom of the sea is for miles covered by deep layers 

 formed of such ball--, which, as Prof. Kjellman re- 

 marks, must be of great importance in forming fresh 

 earth-crusts. All the other species of algas play a very 

 subordinate role compared with the Laminarieffi and 

 Corallinaceas. They are certainly, as regards variety of 

 forms, superior to these latter, as the leaf-weed algas 

 possess only twenty species and the coral algas nine, 

 while other Arctic alga; — with the exception of Dkitom- 

 aceas — have as many as 145 species. In spite, however, 

 of the abundance of the species of the latter, they make 

 but little impression in the algas flora, as they are either 

 too small, or too few in the number of individuals. This 

 being the case, it is only natural that the Arctic sea-flora, 

 particularly owing to the predominance of the Laminarieas, 

 is monotonous in its appearance. This does not indeed 

 apply to form alone, but also to colour. The colour is 

 really sombre, the brown colour of the Laminarieas pre- 

 dominating. The lighter-brown shades are almost entirely 

 wanting. The red algas {Floridece) are not very prominent, 

 with the exception of the coral algas within their special 

 sphere, and their colour is not, as I have observed, of the 

 strongest or purest. The chlorophyll algas are very insig- 

 nificant. The many variations of green — from the freshest 



