On Changes in the Sea and Their Relation to Organisms. 



217 



ing of top and bottom water several times a day; the mixing was not 

 rapid enough, however, to equalize the temperature to the depth of 50 

 meters on a calm sunny day. Palitzsch (1912 6) found the average 



FIG. 2. Currents of the Atlantic Ocean. The arrows show direction. The heavy 

 lines are the courses of two derelicts, drifted by currents and winds. 



O 2 in surface water of the North Atlantic to be 5.9 c.c. per liter during 

 the day and 5.34 at night. 



