186 
Simmo ns, Remarks about tlie Relations of tbe Floras etc. 
Laminariideae , Lessoniideae änd Alariideae. Ali are present in 
tlie north ern Pacific, but the Lessoniideae are totally wanting 
in tlie Polar Sea and the northern Atlantic, wliere we only 
have the genera Chorda , Phyllaria, Saccorhiza (not arctic), 
and Laminaria of the subtribe Laminarieae, Agarum of 
the subtribe Agareae , and Alaria of the subtribe Alarieae. 
Chorda is only with reservation referred to the family 
(cf. also Reinke, 41), but that is a question of minor interest 
liere. Of the tliree species in the genus one is only found in tlie 
Baltic, the two others indeed are found in the Arctic Sea, Ch. 
Filum at a good many different points, but not very far to the 
north, Ch. tomentosa only in Western Greenland. This could 
speak for an atlantic origin, but as Ch. Filum is also found in 
the northern Pacific, there can hardly be thought of any other 
original liome tlian the Polar Sea. 
Laminaria. Of this genus De Toni (14, III) enumerates 
2S species (excl. Hedophyllum), of which 16 are indicated for the 
northern Pacific. 8 for the northern Atlantic. In the Polar Sea 
8 species should grow as indicated in table I. Of these L. gro- 
enlandica , L. Agardhii, and perhaps L. solidungula are only 
arctic, the other species are L. nigripes and L. saccharina , atlantic- 
pac-ific: L. digiiata and L. Jongicruris , somewhat dubious as 
pacific plants; L. cuneifolia only pacific and arctic. The atlan- 
tic species, that do not go into the Polar Sea, however are 
mostly restricted to the northern parts of the european coast \L. 
hyperhorea. Gunneri , (discolor), hieroglyphica). One species, L. 
Bodriguezii is only found in the Mediterranean, two species in 
South Africa ( L . pallida also at St. Paul and the Crozet Islands.) 
The Pacific on the other liand has not less than 10 species of 
its own, also with a northern distribution. Indeed it cannot be 
denied that such a distribution can have its cause in the circum- 
stance that the genus was widely spread already before the 
iceage, but then it becomes difficult to explain, why not a single 
species goes farther down in the Pacific (one species, L. himan- 
thophylla , indeed is mentioned from Southern South America by 
Posteis and Ruprecht (39), but it is never found again, and 
De Toni has it among „species maxime dubiae“). The fact 
that the Lami nariae are entirely absent from the tropic seas also 
points to a northern origin. Brom there the few Southern forms 
must have strayed during the iceage (cf. Setchell, 48, p. 363). 
But why do we not liave any atlantic-pacific species, wan- 
ting in the Polar Sea? I think the answer must be: because 
there are different species formed from the phylembryons that 
have occupied the tertiary Polar Sea and been driven southward 
into different areas. That a lively formation of new species 
has taken place lately, or is still in progress, cannot be doubted 
wlien the great number of nearly allied species is taken into con- 
sideration, that has been distinguished by different authors (cf. 
Setchell. 48 p. 339p If the later writers are right, who have 
ranged a great many of tliem as svnonyms under comparatively 
