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174 H. JONSSON 



both Ascophyllum and F. inflates are sterile, but at that time a few 

 individuals of F. vesiculosus bear young receptacles. From the middle 

 of October until December there are no observations to hand from 

 Reykjavik. The usual course, with regard to these species, appears 

 to be as follows: In the latter part of the autumn the development 

 of the sexual organs begins, and is continued throughout the winter; 

 in March the species are found everywhere with ripe sexual organs 

 and the spores continue their development until the latter part of 

 the summer. 



Kj ell man (36, p. 195) records with regard to Ascophyllum no- 

 dosum in Finmark, that it had numerous receptacles in July and 

 the first half of August, was sterile in the latter part of August, 

 and that new receptacles had begun to appear in October. Foslie 

 (18, p. 64) records with regard to the same species in East Finmark 

 that it has abundant receptacles in July and is sterile in August. 



In the Faeroes (Borgesen, 12, p. 830) Ascophyllum nodosum has 

 young receptacles in December and fruits during the whole summer. 



On the west coast of Sweden the sexual organs begin to de- 

 velop late in August or early in winter (Kylin, 45, p. 106), and by 

 the beginning of June the receptacles have fallen off. 



Fucus inflatus probably behaves in East Finmark in a similar 

 manner as at Reykjavik. Foslie (18, p. 67) mentions receptacle- 

 bearing individuals in June — July and the first part of August. At 

 Spitzbergen it bears fruit during winter and Kj ell man (36, p. 204) 

 found germinating spores in December, January, February and 

 March. 



To Group 2 belong, in addition, probably all the Laminariacece, 

 Rhodochorton Rothii, Polysiphonia urceolata, Halosaccion, Gigartina 

 mamillosa, Odonthalia and probably many more. Petrocelis Hennedyi 

 belongs also most nearly to this group; it has been found producing 

 fruit the whole year, but in spring, summer and autumn only a 

 few fruiting crusts are found, while the winter appears to be the 

 ordinary fruiting period. Chcetopteris plumosa I include, although 

 with doubt, in this group. 



Group 3. To this belong Desmarestia aculeata, which has been 

 found fruiting in October, Rhodomela lycopodioides, Delesseria san- 

 guined and others. 



