5^ 



NATURE 



[May 20, 1875 



that if these prevail the number of other species is relatively 

 less. While, on the other hand, only one species of Laminaria 

 with an entire, and one with a laciniated frond, is found on tlie 

 Swedish coast, there are on the coasts of Spitzbergen and 

 Greenland at least five species of Laminaria. The L. aineifolia 

 of Greenland is about the same size as L. saccharina ; but Z. 

 longicruris, one of the commonest Algae of Greenland, is very 

 large ; the stalk, which is sometimes many ells * long, bears a 

 lamina (frond) of equal size. Some specimens had been seen by 

 Prof. Agardh, which, including both stem and frond, were 

 eighty feet long. Ruprecht mentions an Alaria from the Sea of 

 Okhotsk, the frond of which was about the same breadth as that 

 of the common European form, which had a length of more than 

 fifty feet. From Spitzbergen comes another species of this 

 genus, whose frond is as much as one ell in length and about 

 three ells long ; and also another species several ells long, with a 

 stem as thick as a finger. But it is especially in the north part 

 of the Pacific, on the North American coast, that the richness of 

 the Laminarian forms and their great size are most conspicuous. 

 The species of Alaria, Arthrothamnus, Thalassiophyllum, Aga- 

 rum, and Nereocystis together constitute such a magnificent 

 marine flora, that one feels a difficulty in forming an idea of the 

 smaller representatives of the same group which are found in 

 other seas. Nereocystis Lutkeana has a stalk 270 feet in length, 

 when it swells into a bladder that bears a tuft of fronds which are 

 quite twenty-seven feet in length. In the Antarctic seas the 

 analogues are to be found, the Durvillsea, and Lessonia of Cape 

 Horn, Ecklonia of the South African coast, the species of Macro- 

 cystis, &c., are well-known examples of the large Algas which are 

 found there. 



It is perhaps less surprising that a rich marine flora should 

 appear on the coast ot Spitzbergen wherever a considerable 

 branch of the water of the Gulf Stream follows the coast, and 

 in proportion receives a higher temperature and a greater degree 

 of saltness. But in Greenland it may be otherwise. Cold cur- 

 rents are said to flow along the west coast of Greenland up- 

 wards, as well as on the opposite coast of America downwards, t 

 During a considerable portion of the year the sea appears to be 

 frozen along the coast, and even during the summer months drift 

 ice is reported to be continually seen in the open sea. Under 

 such conditions, although a marine vegetation of large size ap- 

 pears there, it may be assumed that an ice-cold or nearly ice- 

 cold sea by no means prevents a great development of Algse, 

 where the other conditions necessary for their growth are found. 

 One is tempted to believe that the great abundance and size of 

 the marine flora on the coasts of the colder seas, on the one 

 hand, and on the other the richness of the open seas in Diato- 

 macese, are in some measure the cause of the abundance ot 

 animal life which prevails in these regions, and which, in the 

 regularity of its limits, may afford a hint to the expeditions for 

 carrying on the whale fishery that every year employs thousands 

 of vessels. "It has been remarked," says Ruprecht, " that the 

 northern boundary of the large sea animals is found where the 

 coast is most bare of Algse ;" and Maury (" Physical Geography 

 of the Sea ") remarks on the superior flavour of fish from the 

 colder waters, and the greater excellence of the principal fishery 

 grounds of the world, which are all situated in the colder waters. 



In direct opposition to what occurs on the Greenland and 

 Spitzbergen coast, • Ruprecht states that the whole coast of 

 Behring's Sea north of the Aleutian Islands is almost entirely 

 without marine vegetation ; an astonishing statement, as not only 

 on the Aleutian Isles, but also on the American coast to the 

 south of them, the marine flora is rich and is developed on a 

 grand scale. Ruprecht's statement that the whole Arctic sea of 

 Siberia, eastward from the Gulf of Kara to Behring's Sound, is 

 almost entirely without marine vegetation, is almost open to 

 doubt, since Prof. Agardh possesses specimens of two Algse in 

 good preservation which were taken near the mouth of the Lena, 

 and Ruprecht himself mentions another Alga which was found 

 in Behring's Sea. Should it be ascertained that while the rocks 

 of the Arctic Sea, wherever they have been examined, namely, 

 in Norway, Spitzbergen, Greenland, and the coasts of America, 

 present, through the number of individuals and their great size, 



» A Swedish ell is equal to two feet.— M. P. M. 



t In the narrative of the North German Expedition it is stated that on the 

 east coast of Shannon Island, lat. 75° 29' N., drift-wood, identified as alder 

 {Alnus incana, L.) and poplar (P. tremula, L.) was washed ashore, thus 

 plainly showing that the drift-wood of N.E. Greenland comes originally from 

 N, Siberia ; whence, driven into the sea by the strong currents, it floats in a 

 westerly direction north of Spitzbergen, and is carried on until it reaches 

 Greenland, where it takes a southerly course. See vol. ii. p. 537.— M. P.M. 



a peculiar marine vegetation, while, on the other hand, eastward 

 from the Gulf of Kara the sea should be found to be very poor 

 as regards its flora, or even desitute of these large Alga?, perliaps 

 one might under these circumstances form an opinion ihat the 

 Baltic Sea was one of the former gulfs of the Arctic Ocean, and 

 at a later period was separated from it ; hence great interest at- 

 taches to the study of the Algse of the Baltic Sea. The cha- 

 racter of extraordinary scarcity of Algse, which according to 

 Ruprecht characterises the Arctic Ocean, also prevails in the 

 Baltic Sea, where long ranges of rocks, broken like those of the 

 Atlantic into bays, and apparently well adapted to harbour a 

 rich vegetation, are entirely bare of vegetation, while the rocks 

 and rock-pools on the western coast are crowded with Algse. 

 The stunted representatives of marine Algse that most generally 

 appear in the southern and western parts of the Baltic Sea may 

 perhaps have come at a later period from the west, after the 

 Baltic was united with the Atlantic. 



More accurate information relative to the Algse and their 

 alleged scarcity in the Siberian Sea and Behring's Sound are 

 still wanting, but ii priori one is scarcely entitled to assume that 

 the Algce in these localities should differ materially from the 

 uniform character of gigantic size which seems to distinguish 

 the vegetation of the other Arctic Sea. On the other hind, that 

 the Bakic Sea, as well in respect of the number of individuals as 

 of their development, is in direct opposition to the vegetation in 

 the other northern sea, is undeniable. But the (Baltic Seals 

 in a peculiar state. It is an enclosed sea, into which large fresh- 

 water rivers discharge themselves, and a freezing sea, ice-covered 

 during a considerable part of the year, in a great degree prevents 

 evaporation. Both these circumstances may cause the Baltic to 

 be considered almost as a fresh- water basin, into which isalt 

 water flows from the sea almost entirely through the Kattegat 

 and more south-westerly parts, and in the deep water retains 

 some perceptible degree of salt. The influence of the salts on 

 the growth of Algse is at present but little understood, but that 

 they have great influence cannot be doubted. The Alga; which 

 appear in the Baltic cannot be said to indicate a high northern 

 or north-eastern origin. They seem to be the Algae ot the Katte- 

 gat in a dwarf form. Some few species of Alga; appear to be 

 peculiar ; but in this case they do not prove that the Baltic was 

 once a gulf of the Arctic Sea. 



It has been already remarked that a scarcity of forms and 

 abundance of individuals is a characteristic of the marine vege- 

 tation of the northern ocean. Nevertheless it must not be con- 

 cluded from the scarcity of forms which prevails in every 

 separate locality, and of which a few species of each constitute 

 the principal masses of marine vegetation, that the same species 

 prevail everywhere. We should then fall into the error of the 

 older botanists, who thought that they recognised in foreign 

 Algse many well-known forms of the European flora, which 

 outwardly bear a great resemblance to each other. With regard 

 to the northern Laminarise and Fucacete, it may yet be shown 

 that there are analogous — if not identical — species, which appear 

 in different localities, and that the species resembling each other 

 in aspect, also in their habitat resemble each other, and thus 

 constitute representative species. The circumstance that at first 

 one does not perceive the difference between species bearing 

 similar names from different localities, is but weak evidence of the 

 identity of the forms which under the same names were supposed 

 to prove that all these so-named European species actually ap- 

 peared on the coast of Australia ; although we might justly 

 allege this fact as a proof of changes which might have broken 

 the tormer connection between the seas, and so prevented migra- 

 tion from taking place at the present time. So soon as accurate 

 examination is made, important variations are observed to exist 

 between many species which pass under similar names, and some 

 doubt may be entertained, not only whether they constitute 

 entirely different species, but even whether they do not some- 

 times belong to entirely different genera. 



Such representative species appear in many, and in perhaps 

 most genera ; but in Laminaria and Fucus there are some ana- 

 logous forms which are very similar to the eye ; there being in 

 each genus two principal forms only, while each possesses many 

 species which bear a great resemblance to each other. The 

 similarity is, in reality, here so great that many were for a long 

 time considered, and many more may probably even henceforth 

 be considered, as modifications of the same species. 



The difficulty of characterising the species of Laminaria is 

 really very great, not only on account of the great resemblance 

 between them, but also because the species change their aspect 



