JOHN H. RYTHER 407 



with their vertical axes perpendicular to the direction of the prevailing 

 wind. Floating objects will accumulate in the region between the 

 descending components of two such adjoining cells. Under these con- 

 ditions parallel streaks of floating matter are produced ( Fig. 5 ) . ( For 

 a more detailed description of this process, see Langmuir, 1938; 

 Stommel, 1949.) 



BAND OF aCCUMUL/XTION 



Fig. 4. Accumulation of floating material at con\ergence of water masses of dif- 

 ferent density. 



STREAKS OF ACCUMULATED 

 F LOAT I r\JG MATTER 



Fig. 5. Accumulation of floating material by wind-driven convection cells. 



These and other similar mechanisms are undoubtedly important 

 means of concentrating dinoflagellates to the extent to which they are 

 observed in red water conditions. The existence of such processes is 

 indicated by the repeated mention of patches or streaks of organisms 

 in many descriptions of red water (see Table II). Bary (1953) has 

 indicated that convection cells are responsible for the streaky distribu- 

 tion of floating masses of the ciliate Cyclotrichium meunieri in Wel- 

 lington Harbor, New Zealand. 



