The Individual Plant 



dermis of the original leaf). The strongest of them soon 

 gets ahead and promptly flowers and seeds. 



The fortunate one is usually near the leaf stalk, but 

 any of them may succeed in surviving. 



There is of course a want of order about these pro- 

 ceedings, but the orderly nature of plant life has been 

 upset, and one should rather admire the readiness to 

 save the situation, than blame the want of discipline 

 exhibited by the competitors. 



Such an instance as this is very difficult to explain 

 on Weissmann's theory of a special germ plasma, which 

 can alone reproduce a new plant, for the leaf has im- 

 provised not one but several potential germ plasmas. 



Moreover internodes (for instance, of Ceropegia 

 Woodii), when separated or cut away from the parent 

 plant, can produce tubers and eventually flower. Root 

 cuttings are by no means unusual, and give rise to 

 quite normal plants. 



It is very hard to believe then in the existence of 

 an " immortal " germ plasma in any way separated 

 from ordinary protoplasm, though of course the proto- 

 plasm of pollen grain and egg cells differs from that 

 found in ordinary cells (compare Darwin). 11 



Competition can be clearly distinguished amongst the 

 twigs of a tree, all of which seek the light. 



The same struggle goes on between the twigs on one 

 branch, or the leaves on one twig, and even to some 

 extent between the flowers of one inflorescence. It is 

 surely true that every cell in the plant is also competing 

 with its neighbours for water nourishment, oxygen and 

 the like. This has been long insisted upon by Rolf and 

 others, but seems never to have been quite appreciated. 



1 Hansgirg. 2 Pringsheim. 3 Blackman and Matthaei. 



4 Mahevv et Combes. 6 Svendsen. 6 Jeffrey. 



7 and 8 Nemec. 9 Kupper. 10 Winkler, Figdor. 

 11 Darwin. 



156 



