ROMANCE OF DEPTHS OF THE SEA 119 



It has been observed by Hansen that plants in 

 the sea are often so rare that it is difficult to 

 understand how the animals can get enough 

 nourishment, and yet the green, and as a rule 

 microscopic, algae have to produce enough food 

 to support every single marine animal from the 

 surface down to the deepest abyss. Hansen 

 worked largely with vertical tow-nets, through 

 whose meshes these minute Coccolithophoridae 

 passed with ease. But taking everything into 

 consideration, one would not feel very happy 

 about one's food supply if one were a marine 

 animal, and thoroughly understood the economics 

 of the ocean. The margin would strike one as 

 very small. 



Lohmann has studied, with the greatest minute- 

 ness and care, the quantities of all the Plankton 

 organisms in Kiel Bay throughout a year, and 

 he has calculated the volume of the various 

 groups in the Plankton in the different water 

 masses of this area at all seasons. In the winter 

 months the algae seem easily outnumbered by 

 the animals, and from December to February 

 they scarcely form a third of the total Plankton, 

 the floating and drifting living organisms. In 

 the summer months, however, they preponderate 



