144 



THE MECHANISM OF LIFE 



blance to that of living organisms. Is it possible to doubt 

 that the simple conditions which produce an osmotic growth 

 have frequently been realized during the past ages of the 

 earth ? What part has osmotic growth played in the 

 evolution of living forms, and what traces of its action may 

 we hope to find to-day ? Osmotic growth gives us fibrous 

 silicates, phosphatic nodules, corals, and madrepores ; it also 

 gives us formations which remind one ' of the " atolls," 



o 



calcareous growths rising like a crown out of the water. 



FlG. 58. — Photomicrograph ol an osmotic leaf 

 showing the cellular structure. 



The geologist may well consider what role osmotic growth 

 may have plaved in the formation of the various rocks, 

 siliceous, calcareous, barytic, magnesian, the fibrous and 

 nodular rocks and atolls. The palaeontologist relies on the 

 different forms found in his rocks to classify his specimens; 

 from the existence of a shell, he concludes the presence of life. 

 Since, however, forms which are apparently organic may be 

 merely the product of osmotic growth, it is evident that he 

 must reconsider bis conclusions. The same may be said of 

 the various forms of coral or of fungoid growths. In the 



