MARINE ALGAL VEGETATION 



The Fruiting-period of the Species (.continued). 



179 



Chsetomorpha tortuosa 



C. Melagonium 



Rhizoclonium riparium . . . . 

 Spongomorpha vernalis 

 Acrosiphonia albescens 



A. incurva 



A. bystrix 



A. flabelliformis 



A. penicilliformis 



Cladophora rupestris 



C. hirta 



C. sericea 



C. glaucescens 



C. gracilis 



Gomontia polyrrhiza 



Ostreobium Queketti 



Cyanophycese. 

 Pleurocapsa ametliystea .... 

 Pleetonema norvegicum. . . . 

 Phormidium autumnale. . . . 



Spirulina subsalsa 



Calothrix scopulorum 



Rivularia atra 



Spring 



+ 



+ 

 + 



+ 



+ 



Summer 



Autumn 



_ 





_L 



— 



_L 



— 



+ 



+ 



+ 



+ 



+ 



+ 



+ 





+ 





— 



J_ 





+ 



+ 



+ 



_L 



+ 



— 



— 



By looking through the above table it is seen that in the case 

 of a number of species the fructification-period is of long extent. 

 Some nine species have been found fruiting all the year round, 

 but I presume that by future investigations it will be proved that 

 many more species bear fruit during the whole year. Kj ell man 

 (36) mentions 11 species which bear fruit all the year round in the 

 Arctic Sea, and Rosen vinge (63) mentions 6 species which fruit 

 all the year round along the coast of Greenland, and he adds that 

 probably there are many more. 



If we consult the table as to which season of the year is richest 

 in fruit-bearing species it is easily seen that summer stands highest, 

 with 64 °/o of the total number of species ; then comes spring with 

 42 %, and after that autumn with 33 °/o. As the conditions during 

 winter are so very little known no percentages can be given for 

 that season. 



It is well-known (Kjellman, Rosenvinge, Borgesen) that 



12* 



