224 KJELLMAN, THE AZGM OF THE ARCTIC SEA. 



rences between these algte, leaving it undecided whether these are differences of species 

 or of age. However, in Bidrag till kdnnedomen om Spetshergens Alger, Tilldgg, he 

 seems to have abandoned his earlier view and to regard the algae in question as different 

 forms of the same species. His description may be applied to both of them. In my 

 works on the marine vegetation at Spitzbergen and in the eastern Murman Sea I have 

 adopted the latest view of J. G. Agakdh and accordingly referred all the Phyllaria 

 occurring in those regions to one and the same species, Saccorhiza dermatodea. I must 

 now relinquish this opinion. After having seen on the coast of Finmarken a great 

 number of Phyllarice in different stages of development and having, on account of the 

 observations I made there, again carefully examined my collections from other parts of 

 the Polar Sea, I have arrived at the conclusion that there exist in the Polar Sea two 

 species of Phyllaria, the one identical with the plant recorded by J. G. Agakdh (Spec. Alg.), 

 J. E. Areschoug, and Farlow as Laminaria (Saccorhiza) dermatodea, the other identical 

 with Laminaria Lorea J. G. Ag. I have been compelled to this opinion most of all by 

 the fact that even among very young plants — what' might almost be called germinat- 

 ing plants — there are to be observed two sharply distinct species. In some the stipe 

 is longer, more or less distinctly marked from the lamina, the lamina is oblong, ovato- 

 oblong or broadly lanceolate, darkbrown in colour, only little translucent, with very 

 few short-haired cryptostomata. These are young plants of Phyllaria dermatodea. The 

 young plants of the other species — I possess such plants in considerable number from 

 Spitzbergen as well as from the west coast of Novaya Zemlya — have a very short 

 stipe passing without definite limit into a narrow, sometimes almost filiform, linear, or 

 more usually lanceolate lamina. Their lamina is thin, very light brown, almost yellowish- 

 brown, perfectly pellucid with numerous long-haired cryptostomata. These plants be- 

 long to the alga described by J. G. Agardh under the name of Laminaria lorea, which 

 even when older has the same shape and colour of the lamina as the young plants and whose 

 lamina is pellucid with numerous cryptostomata. Older specimens of the two species are 

 easily distinguished from each other by several good characteristics. In Ph. lorea the 

 stipe collapses in drying, and becomes flat, thin, almost membranaceous, and brittle; 

 even in very large specimens it has the same colour as the lamina, being pellucid like 

 this. In older specimens of Ph. dermatodea the stipe is far more solidly built, dark- 

 brown, opaque, flat upwards, but almost terete downwards. With this outward differ- 

 ence of the stipe there is connected a difference in its structure, which, as far as my 

 observations go, is essential and lasting during the whole life of the plant. In Ph. 

 dermatodea the stipe is composed of l:o a layer of cortical cells which are square or 

 tangentially rectangular in transverse section, very rich in endochrome, with the outer 

 wall cut.iculated; 2:o inside this a thick layer of large thin-walled cells which increase 

 inwards in length and also in width, and farthest in are several times longer than wide; 

 3:o a central layer formed of almost isodiametrical cells of different sizes and with 

 thinner walls than the cells of the middle layer; 4:o very long tubular cells, with very 

 thick walls, sometimes simple, sometimes branched, which in transverse section are seen 

 to be arranged circularly on the limit between the middle and the central layer. These 

 tubular cells occur even in very young individuals though in little number, but become 



