H4 STUDIES IN INSECT LIFE, ETC. 

 yet, in comparison with their bulk, their loco- 

 motor organs are really moving them along as 

 fast as the legs of a cantering pony. Planktonic 

 animals are, however, readily moved by the 

 waves, by the wind, by the tide, but they have 

 little control over their translocation. Now a 

 great deal of the Plankton is confined to the 

 surface of the sea, and here if we examine the 

 fauna we shall find innumerable animals of very 

 various kinds. We have first of all a large part 

 of the Plankton consisting of such organism as 

 Sagitta, many marine worms, tunicates, small 

 Crustacea such as copepods some of them as 

 brilliant in coloration and design as any fire- 

 work many jelly-fishes, certain molluscs, and 

 a few fish. But most important of all the mem- 

 bers of the permanent Plankton are the protozoa 

 and the minute algae which swarm on the surface 

 of the sea. 



These algae are the source of all life in the sea. 

 They alone are capable, in the sunlight, of build- 

 ing up organic compounds out of the inorganic 

 matter around them, and on them the whole of 

 the marine fauna, from whales and the largest 

 fishes to the microscopic, unicellular protozoa, 

 whether floating on the surface or living in 



