450 



bearing such narrow sporophylls occur on exposed coasts; in more 

 sheltered localities the sporophylls get broader and the same often 

 applies also to the lamina. These specimens thus constitute a 

 transition to the broader f. pinnata. 



This species occurs gregariously in enormous masses from 

 about low-water mark to several fathoms below it, but in particu- 

 larly exposed piaces it can grow somewhat above low-water mark, 

 and in narrow rock-clefts washed constantly by the sea it may be 

 found up to 1 — 2 metres above sea-level at low tide. It grows by 

 preference along open sea-shores, but may also occur in the interior 

 of fjords in more sheltered localities, and is most commonly met 

 with on steeply sloping or quite perpendicular rock-faces and in 

 faet on rocks in general. Fructifying specimens were found in 

 May, June, July and November. This alga undoubtedly attains to 

 its highest development in spring and early summer. 



With regard to its change of leaves Wille writes in »Beitråge 

 zur physiologischen Anatomie der Laminariaceen«, Christiania, 1897, 

 p. 7: — »dieses Endblalt fållt jeden Herbst ab und wåchst von 

 neuen heraus im Laufe des Winters«, but I do not think that this 

 is always so, as at any rate along the Færoes I never came across 

 specimens which showed the slightest indication of a regular change 

 of leaves as is the case, e. g. in most of the Laminaria- species. 

 My own observations lead me to think that the leaf keeps on 

 growing at its base during the greater part of the year, while the 

 apex is continually so to speak worn away by the force of the 

 waves. All the specimens I have seen had leaves which were al- 

 ways fresh at the base, while towards the apex they gradually 

 become older and more and more tattered and the segments were 

 gradually torn away so that the midrib only was left and when 

 examined more closely the latter also proved to be scratched and 

 worn at the apex (cfr. fig. 84). It is true that I have only seen 

 specimens from April to August and October to December and it 

 is very probable that the leaf grows more rapidly at certain seasons, 

 but I feel convinced that a regular change of leaves does not take 

 place. I think Wille's observation (based on the material from 

 Mandal gathered in August) must doubtless be regarded as a result 

 of the warm season which is less favourable to this species at so 

 southerly a habitat. 1 



1 In connection with this 1 would call attention to the faet that in the mu- 

 seum in Copenhagen wc have some specimens gathered by Dr. Hosenvinge near 



