56 



THE TISSUES OP PLANTS 



tion of cells already existing, wHch causes growth or the 

 extension of the parts of plants. In this respect precisely, 

 the same laws operate in plants composed of a single row 

 of cells, as when nature works on a more enlarged scale. 

 The most important physiological truths may therefore be 

 learned from vegetation apparently insignificant. " Natura 

 miranda est maxime in minimis."* 



Fig. 13. 



^^ 



'iiPig 



Branclmig summit of a fresh water plant, Conferva glomeraia, -magnified, 

 showing at upper a, the partitions forming by tlie infolding process, and at 

 lower a, the partitions complete, 



* Linnseua. 



