Existence of Plankton 



39 



Murray and Hjort, 1911, copyright Macmillan & Co. 



Fig. 2.7. Globigerina buUoides, a planktonic protozoan belonging to the order 

 Foraminifera. The largest sphere of the shell is about 0.5 mm in diameter. 



TABLE 1 



Comparison of Sinking Rates of Three Types of Plankton Organisms 

 WITH Those of Spherical Sand and Silt Particles 



Since the density of the water environment is closely similar to that 

 of organisms living in it, the reader will not be surprised to learn that 

 slight changes in the former often have important consequences in 



