OCEAN CURRENTS 135 



information in the case of the waters of the North European 

 Seas.* The "weed" of the Sargasso Sea is an example of 

 natural drift bodies. The large pods of a mimosa (Entada 

 gigalobium) which is indigenous to the Antilles are frequently 

 found to have drifted across the Atlantic to the shores of the 

 Azores, Canary Islands, Ireland, Iceland, and even the coasts 

 of Norway, North Spitsbergen, and Nova Zembla. Timber 

 from the forests of Northern Siberia has been found to drift 

 across the Arctic Sea to Northern Iceland and Greenland. 

 Formerly, when their shores were more wooded than now, 



FIG, 25. DRIFTING WRECKS IN THE NORTH ATLANTIC. (KRUMMEL.) 



West Indian mahogany and St. Lawrence firs and pines 

 drifted across the Atlantic as far as the North Sea coasts of 

 Europe. 



Another source of important information as to ocean 

 currents is furnished by icebergs, of which one-fifth of the 

 bulk usually projects from the water. Derelict ships have 

 also afforded information. 



* See Johnstone, "Conditions of Life in the Sea," p. 151 ei scq. Cam- 

 bridge University Press, 1908, 



