206 LIVING PLANTS 



forward in its growth the living contents 

 of the rear cells are graduall_v withdrawn, 

 and the effete skeleton of cell-walls disinte- 

 grates ; and in a similar way the appendages 

 of leaf and root serve their purpose and are 

 discarded, as a stag sheds his antlers. Al- 

 though leaf and root and posterior part of 

 stem repeated^ disappear the plant retains 

 its identity as an individual. When the drop- 

 ping away of the end of the rhizome has 

 involved a branch, the two advancing ends 

 becomeentirely separate individuals, a method 

 of increase that some species find so eflRcient 

 that they rarely or never produce seeds or 

 even flowers. It is no fiction to say that such 

 a plant never dies. It is compelled to drop its 

 appendages and hibernate during the incle- 

 ment season, but its physiognomy remains 

 the same whatever age it may attain. 



It has been shown in a previous essay (page 

 101), that increasing the food supply, or of 

 other external factors favorable to growth, 

 tends to prolong the life of the individual 

 and to decrease the amount of reproduction. 

 This is evidentl}^ moving, although but a step, 

 in the direction of ideal conditions for the 

 even display of vital energy. 



These and other reasons which can not find 

 place here lead us to think that both senility 

 and excessive increase are riot inherent char- 



