190 PROCEEDINGS OF THE AMERICAN ACADExMY 



Kjellraann says * that the proper season for the formation of zo- 

 ospores in this species is in September or the beginning of October, 

 on the Norwegian coast. At Spitzbergen he found specimens with 

 zoosporangia in July and August, and at Nova Zembla in July. 

 There is apparently in the more northern regions an earlier ripening 

 of these bodies. 



The fruit occupies about the lower half of the blade in the well de- 

 veloped specimens. The collection of sori, or cloud-like patches of 

 fruit, covers the surface on both sides at the very base of the frond, 

 but separates above into irregular-shaped blotches of considerable size. 

 When the water has evaporated from the surface of the frond, these 

 Sori have a peculiarly soft and velvety appearance, and are of a some- 

 what litihter brown color than when wet. When dried, the mature 

 plants are of a decidedly black color, but tlie sori are even blacker 

 than the frond, and may thus be detected readily even in herbarium 

 specimens. 



De la Pylaie f describes the fruit as entirely covering both surfaces 

 of the frond, and as occurring toward the end of autumn. AreschougJ 

 says : " Fructificatio . . . non format maculas extensas 1. fascias, nt 

 in Laminariis, sed maculas minutissimas fere punctiformes, nunc sepa- 

 ratas, nunc approximatas, quo fit, ut cum siccata est, lamina farina 

 nigrescente conspurcata videatur." The specimens from the New 

 England coast do not agree with this description, as may be seen from 

 what has been said above. § 



Specimens are cast ashore in the greatest numbers from November 

 until May. I have generally found them most abundant in February. 

 A specimen thrown ashore at Lynn, Mass., February 9, 1890, was in 

 very perfect condition, and so will serve as a good illustration of these 

 very old plants. The lower part of this specimen is represented of 

 the natural size in Figure 10. It measured 70.5 cm. in length, and 

 the holdfast was about 2 cm. in diameter. The primitive disk was still 

 present, although mucli shrivelled and wrinkled. Of the first set of 

 hapteres three were present in a good state of preservation on one 

 side, and the places where the other two had been were to be seen on 

 the other. There were nine hapteres present in the outside set. All 

 the hapteres were unbranched. The stipe was 12.1 cm. long. It was 

 cylindrical at the base and flattened at the top. The blade had the 



* Arct. Algr., p. 225. t Fl. Terre Neuve, p. 49. 



t Obs. Phvc, Part. III. p. 12. 



§ Cf. also kjelhnan, Spetsb. Tliall., II., p. 14, 1877. 



