826 



the autumn months of 1897, brought home by Mr. Helgi Jonsson, 

 as well as by Ibe in formalion he has also given me. With these 

 as basis we may safely conelude, that the algal vegetation of the 

 Færoes is mnch richer and more luxuriant in summer than in 

 winter; the greater development probably begins early in spring 

 and continues into July or August, when the greatest luxuriance is 

 reached, then it decreases again. But on account of the great uni- 

 formity of the Færoese climate, the variability of which, parti- 

 cularly as to temperature, is regulated in the sea itself, this varying 

 development according to the seasons is hardly so great here as in 

 many other piaces with a cold temperate climate. 



The algal vegetation of the Færoes agrees well, as regards the 

 richer development in summer, with what is known even in Arctic 

 seas, where the period for the growth of the algæ is at the brightest 

 time of the year, for instance, on the coasts of Greenland, whilst 

 their resting period begins at the beginning of winter (see Rosen- 

 vinge 71, p. 239). On the other band the algal vegetation of more 

 Southern countries is much less developed in summer. This may 

 be remarked even on our own coasts, where the vegetation in shal- 

 low water is more luxuriant during the months of spring and au- 

 tumn, but less so during the warmest summer days; and in the 

 Mediterranean Sea the littoral algæ-vegetation is, according to Ber- 

 thold (5, p. 426), very poor in summer, but rich and well developed 

 during the months of winter and spring. 



DURATION OF LIFE. PERENNIAL, ANNUAL AND SHORT-LIVED 

 SPECIES. 



As on the coasts of Greenland, the algæ growing on the Fær- 

 oese coasts are for the most part certainly perennial. It is impos- 

 sible for the time being, however, to make any reliable comparison 

 between the perennial and the annual species, as our knowledge of 

 the developmental history of a great many species is still very 

 imperfect. 



On the other band, several species are certainly or most prob- 

 ably annual. To these belong: Pnrphijra umbilicalis and probably 

 other species of Porphyra, Chantransia (9) , Erythrolrichia (9); of 

 brown algæ may be mentioned: Chorda filiim and C. tomentosa, 

 Castagnea virescens, Scytosiphon lomentariiis , Dictyosiphon Ekmaiii, 

 Punctaria plantayinea, Leathesia difj'ormis, Phyllitis fascia and Ph, 



