THE TEEMING LIFE OF THE WATERS 



by the total of successive generations of these Diatoms 

 and Copepods is equivalent to nearly 150 grammes per 

 square metre of the sea's surface. None of our well- 

 cultivated fields, area for area, could do more. 



This extraordinary world has been given a name: 

 the word " plankton " has been created especially for 

 it, and this term is now universally used. But it only 

 expresses a part of the reality. Impressed by the way 

 these floating beings are carried about by the currents, 

 thus forming an immense mass of wandering individuals 



Fig. 1. — Common Dinoflagellates of the plankton. Left, a Ceratium ; 

 right, a Peridininm. These creatures, which exist in great numbers 

 and are invisible to the naked eye, are very tiny, varying according 

 to species, from fa to fa of a millimetre. 



without any fixed home, the author of the name, the 

 oceanographer Hensen, expressed that state by the 

 word plankton, which is related etymologically to 

 " planets ", stars which wander about the heavens. 

 But this name does not take into account the principal 

 characteristic. It forgets the strange, preponderating 

 quality which these creatures possess of floating con- 

 tinually, remaining suspended in the water for their 

 whole existence, from birth to death, never settling 

 and never resting, a characteristic which is unique, 

 which makes of this plankton a strange living assemblage 

 with no corresponding equivalent in life on land. 

 6 



