823 



After having thus taken into consideration what serves to sup- 

 port the theory of the transport of algæ across the sea, we must, 

 however, admit that on the whole we know very little with certainty 

 about the matter — and so far, our conclusions must necessarily 

 be hypothetical. Taking everything into consideration, however, 

 it seems probable to me, and at least not incompatible with the 

 real conditions, that perhaps all the algæ of the Færoes have been 

 transported across the sea by the agency of the currents. They 

 can either have floated by themselves or have been fixed to various 

 objects floating in the sea. The agency of birds must perhaps also 

 be taken into account. Floating ice has also perhaps contributed 

 to the distribution of the algæ towards the end of the glacial period 

 and shortly after. Nowadays the floating ice is of no importance 

 to the Færoes. 



There is one further evidence, which indirectly but strongly 

 confirms the hypothesis concerning the immigration by sea — viz. 

 the faet, that hardly any island has not got its algæ-vegetation, 

 even those at the greatest distance from the coast and of volcanic 

 origin or built by corals. Jan Mayen serves to prove this by its 

 algal vegetation, which is certainly very poor, so far as we yet 

 know, but still has species not only from shallow, but also from 

 deep water. 



It is naturally more difficult for algæ to pass across the sea 

 than to travel along a coast. This serves to explain the faet, that 

 several species common on the coasts of the adjacent countries, 

 are wanting on the coasts of the Færoes, it likewise seems to me 

 to very clearly refute the hypothesis of a postglacial land-bridge. 

 Fiiciis serratus for instance is totally wanting on the coasts of the 

 Færoes, and this is the more worth mentioning, because this alga 

 is very common along all the coasts of North Europe. On the 

 Shetland Isles for example, which are nearest to the Færoes, it grows 

 abundantly. That this species has not spread so far as to the 

 Færoes is certainly solely due to its want of air-bladders, which 

 prevents it from floating by itself on the surface of the sea. The 

 species of Fiiciis found in the Færoes are on the other band al- 

 ways or at least sometimes provided with air-bladders and are thus 

 able to float. It cannot surely be denied, that the Færoes offer 

 an excellent locality for Fiiciis serratus, if it should succeed in 

 reaching so far. It is therefore probable, that it would have grown 



