276 PLANT-LIFE 



direction of the- force of gravitation. The root is posi- 

 tively geotropic, while the stem exhibits negative geo- 

 tropism. One is doubtful if the plain reader will con- 

 sider this a sufficient answer to the question as to how 

 it is that the root grows downwards and the stem 

 upwards, and even were one to add the factor of " in- 

 herited experience ". in plants, the sense of mystery 

 might only be deepened. " Geotropism " certainly 

 stands for something, but the use of a learned term 

 does not necessarily imply a full explanation of phe- 

 nomena in which Life is a more potent force than 

 ordinary gravity. 



Just here it is advisable for us to consider briefly, 

 with the aid of some common examples, the strenuous 

 way in which green plants may be said to affirm Goethe's 

 demand for " Light, more light." The struggle for 

 light and air is an important part of the silent warfare 

 in which plants engage a warfare waged relentlessly 

 and without scruple. In this struggle it matters not 

 to the combatant who fails so long as he succeeds. 

 The Daisy on the lawn is a familiar and conspicuous 

 example of a relentless plant warrior, a notable illustra- 

 tion of the Biblical principle, " A little one shall become 

 a thousand, and a small one a strong nation." This 

 plant increases as successfully in a vegetative manner 

 as by the agency of seed. Its leaves are arranged in 

 rosette form, their shape and arrangement being such 

 that, without interfering with or shading others unduly, 

 each one receives the maximum of light. But while 

 the rosette receives all necessary light, it takes care 

 that any grass attempting to grow beneath it shall get 

 none at all; indeed, it literally suffocates the grass that 



