142 



LIFE IN THE SEA 



[CH. V 



and in the presence of carbon food-stuff they can 

 synthesise it to proteid. We may then speculate 

 further and think of a continued evolution of this 

 mode of nutrition; that by-and-by the majority of 

 plants and other holophytic plankton organisms may 

 become freed from the shackles of inherited modes 

 of nutrition; and become able to assimilate atmo- 

 spheric nitrogen, just as their ancestors, who felt the 

 pinch of carbon hunger became able to assimilate 

 atmospheric carbon dioxide, when that gas was a 

 residue as nitrogen is at the present. In this way 

 we can imagine the nitrogen hunger of marine or- 

 ganisms becoming at last satisfied. 



The Lucas Sounding Lead and Snapper. 



