Uses of Marine Algcz in Japan 
ii 5 
N a paper published last year in Postelsin ,* K. Yendo points out 
that owing to the long and irregular coast line of the Japanese 
islands, a large proportion of their inhabitants are brought into 
contact with the sea, and hence marine algae have been utilised for 
all sorts of economic purposes. Yendo enumerates a number of 
these seaweeds, and it will perhaps be worth while to draw attention 
here to a few of the more important. 
Laminaria is much used as a food-plant, and in 1894, over 18,000 
tons were exported, chiefly to China. The Laminaria fishermen 
wind up the fronds, which sometimes form belts a hundred feet in 
length and two feet in width, by means of long poles with forks or 
sickles at the end. Yendo’s paper is illustrated by Japanese colour 
prints, one of which is a most dramatic representation of the Ainu 
people gathering Laminaria. 
Porphyra is actually cultivated on a large scale for food! 
“ Slender, bushy twigs are planted in regular rows in shallow and 
brackish water. Enough space is left between the rows to permit 
the passage of canoes. Late in winter or early in spring the 
Porphyra plants gather on the twigs.” The tiny purple 
fronds are collected, washed, and dried in layers upon reed mats. 
They adhere together into a sheet by means of their own gelatine, and 
these sheets are peeled off the mats, folded and sent to market. 
Next to Laminaria and Porphyra the most useful Japanese alga 
is Gelidium contemn , from which agar-agar is prepared. 
Various kinds of Sargassum are used as manure, and one 
species, S. enerve, which becomes green on drying, is employed, 
intertwined with Laminaria , in the New Year’s day decorations. 
Yendo says that the plants occupy much the same place in Japanese 
life that the holly does among the English, 
Different species of Chondrus and Gloiopeltis are boiled up into 
a kind of laundry starch, and numbers of other seaweeds, are 
utilised in decoration, or eaten as salads, sauces, etc. 
The point to which the employment of algae has been 
carried in Japan may be gathered from the fact that Yendo alludes 
to nearly thirty different species as economically important, 
although he distinctly excludes from his list those of restricted use. 
A. R. 
1 Postelsia . The Year Book of the Minnesota Seaside Station, 1901, 
St. Paul, Minnesota, 1902. 
