817 



oes, the immigration of algæ from there is probably of but small 

 importance. It is probable, bowever, tbat the Færoese species of a 

 more nortbern distribution e. g. Halosaccion ramentacenm and Ptilota 

 pectinata, wbicb are distributed more specially in tbe nortbernmost 

 part of tbe islands bave been carried this way to tbe Færoes. 



It is my opinion Iberefore tbat 1) circumstances are some- 

 wbat favourable to marine algæ being carried across 

 and over tbe sea to tbe Færoes from tbe west and north 

 coasts of Ireland, from the west coast of Scotland, from 

 tbe Hebrides, etc, 2) tbat algæ can possibly be carried 

 from tbe west coast of Norway, and 3) tbat algæ can very 

 well be introduced from East Iceland (probably also from 

 other parts of Ibis island). 



Having tbus discussed tbe possibility, tbat objecls floating in 

 tbe sea can be carried to tbe Færoes from tbe coasts of tbe ad- 

 jacent countries, wben circumstances are favourable, we may en- 

 quire into what enables tbe algæ to float for a long time in 

 tbe sea. One reason is, tbat tbey are in themselves able to 

 float for a long while; anotber, tbat tbey are attached to floating 

 timber, etc. 



As to tbe first reason, there are not a few algæ, especially lit- 

 toral algæ, with air-bladders or with a thallus partly inflated witb 

 air^, which keep them on tbe surface of the water for some lengtb 

 of time. Almost everywhere in the sea one can meet with floating 

 seaweed (comp. tbe above-mentioned observation made by Gran) 

 often far from their habitats. Kjellman says (48, p. 73), tbat he 

 bas found Ascophijlhim nodosiim and Fucus vesiciilosiis floating in 

 tbe sea at different latitudes between Norway and Spitzbergen; and 

 on the south coast of Spitzbergen he has collected Ascophyllnm witb 

 numerous Pohjsiphonia fasfigiata. He bas not found these algæ fixed 

 to any substratum, but others bave stated tbat tbey grow there; at 

 any rate tbey must bave been carried there by the Gulf Stream. It 



^ Of the algæ from the Færoes there are in the first place nine brown algæ 

 which are either always or at any rate more or less frequently supplied with air- 

 bladders: Ascophiilhim nodosnm, Fnciis vesiciilosiis, F. inflatus, F. spiralis, Himan- 

 Ihalia lorea, Halidrys siliqiwsa, Laminaria færoensis, Scijtosiphon lomentariiis and 

 Chorda filiim. Moreover, there are the species of Enteromorpha and perhaps a 

 few more brown and red algæ. Here the Zostera must also be mentioned; it is 

 well known that its thallus floats excellentl3\ These species, which are almost 

 all rich as to numbers, float easily, and on these different algæ and Zostera there 

 often, indeed almost always, grow a great many different epiphytes and endophytes, 

 which are likewise carried about in the sea. 



