830 



winter, and fructify the next summer. AscophijUiim nodosiim, for 

 instance, has young receptacles in December: it has been found with 

 ripe receptables in April, and fructifies constantly during the sum- 

 mer; just the same seems to be the case with Fiicus inflatus and 

 Fiiciis vesiculosus; Himanthalia lorea has been found with young re- 

 ceptacles in April, and they become perfectly ripe in July-September. 



Other species e. g. Ectocarpus lucifugus, Sphacelaria cirrhosa, 

 Elachista scutnlata . Desniarestia aculeala etc. have only been found 

 with ripe sporangia during the months of autumn, others, e. g. 

 Ectocarpus tomentosoides in the end of the winter and more rarely 

 in spring; species of Urospora, Monostroma Grevillei etc. during the 

 months of spring and early in summer. 



Lastly, it seems as if a great many algæ are able to fructify 

 all the year round; several of the above mentioned short-lived spe- 

 cies, e. g. Porphijva umhilicalis, also Chantransia secnndata, Callo- 

 phijllis laciniata, Euthora cristata, Delesseria sinuosa, Ectocarpus lito- 

 ralis, Elachista fucicola, and probably many more may serve as 

 examples. 



Just as the period of life and growth of several algæ is 

 prolonged under the influence of the Færoese climate, the fruit- 

 bearing period is often likewise of longer duration liere than in 

 more southern countries; this is similar to what Rose uvinge 

 has observed in Greenland. As illustrations of this may be men- 

 tioned: Rhodochorton Rothii which in Denmark only fructifies during 

 the winter months, but which has been found with tetraspores even 

 in June and July on the Færoes; Ascophyllum nodosum which here 

 in Denmark only fructifies during the winter, but which has ripe 

 reproductive organs all the summer on the Færoes as in Green- 

 land, and Delesseria sinuosa of which the same may be said. 



On the whole, the fruit-bearing period seems, as regards several 

 species, to occur at other seasons than in more southern countries, 

 and the Færoes seem also in this to occupy an intermediate posi- 

 tion between Greenland, where still greater differences are observed 

 according to Rose uvinge, and more southern countries. 



Before closing this treatise I would here express my grateful 

 thanks to Professor War min g and Dr. L. Kolderup Rosen vinge, 

 my »Opponenter« ex officio, who by their thorough criticism of the 

 Danish issue of my work have greatly contributed to improve the 

 present edition. 



