1917] Collins,— The Sargasso Sea 83 
is a colored plate of the Pterophryne in G. B. Shattuck, The Bahama 
Islands, Pl. LV, 1905. In this the fish is painted in colors brighter 
than in.nature, the gulfweed in duller; but even so, the mimicry is 
striking. 
Is there reason to suppose that the Sargasso Sea contains any other 
species of algae?’ I think that there is evidence that Ascophyllum 
nodosum (L.) Le Jolis, if not actually adapted to a pelagic life, shows a 
tendency towards it. While never found attached at Bermuda, it 
is occasionally found among floating Sargassum, indeed one is almost 
sure to find it by going carefully over any large mass of the latter. 
It is always without basal disk, and the lower part is in the same 
worn condition shown by the Sargassum. In one instance the lower 
end of the frond showed a cup-shaped cavity, caused by internal 
decay, and in this were three individuals of the barnacle, Lepas 
anatifera, an organism never recorded on Ascophyllum under normal 
conditions, and of a size indicating an age of not less than two 
weeks. This indicates only the shortest length possible for its floating 
condition. It isa common shore plant from the arctic regions to New 
Jersey on the American coast, to the Bay of Biscay on the European. 
It seems less likely that it could come from the former, crossing the 
rapid current of the gulfstream, than that it should come from Europe, 
from which a westerly current passes just south of Bermuda. As to 
its occurrence with Sargassum elsewhere, Bouvier! says, “(a et la, 
parmi les Sargasses, on rencontre quelques fragments de Fucus nodo- 
sus, arrachés certainement aux rivages des Canaries, de Madère ou 
des Açores.” To be sure, Sauvageau, Sargassum bacciferum, p. 1083, 
points out that the Fucus (Ascophyllum) has never been reported grow- 
ing at the Canaries, Madeira or the Azores; but Bouvier’s erroneous 
assumption does not invalidate his record of the occurrence of the 
plant. Bérgesen writes me “Professor Gran has most kindly com- 
municated me that Ascophyllum was found in the northern part of 
the Sargasso Sea, and rather abundant.” It seems probable then 
that Ascophyllum nodosum occurs, though in quite small quantity 
relatively, throughout the Sargasso Sea. But in one important respect 
it differs from the species of Sargassum; it is frequently found in 
fruit, sometimes luxuriantly. If, as is now generally believed, fructi- 
fication in algae is a response to changed conditions, usually condi- 
e 
1 Bouvier, Bull. del’ Institut Oceanographique, 1907, No. 93, p. 35. 
