Page:Polar Exploration - Bruce - 1911.djvu/81

Rh as a rule, covered with white snow, there are no bears to benefit by being lost among yellowish patches of their own colour. Later on I will say more about bears: just now let us remember their wonderful resemblance to the yellow diatom patches on the Arctic floes.

The diatoms of the Arctic floes and pack ice are also otherwise interesting. Certain species and varieties of diatoms found on the Greenland pack, which drives southward down the east coast of Greenland, are identical to those found near Behring Strait, and this was one of the reasons that made Nansen confident that the Fram would drift across the polar basin from the Siberian Islands to the Greenland Sea.

Now all these diatoms that have been referred to are distinctly associated with sea-water ice, and according to Cleve the Arctic ones "take their origin from salt water," and not from the land. In Antarctic ice the diatoms are all marine forms: but they probably live in the sea water permeating the ice in the lamina, which occurs in the pieces of pack ice at sea-level, below the surface snow, since those floating freely in the Antarctic seas appear to be different species from those found in this lamina.

On the surface of the sea, in all parts of the world, diatoms and other algæ occur, and