18 APPLIED BIOLOGY 



that it dies and the lifeless body soon changes to the con- 

 dition of inorganic substances which make up air, water, and 

 the soil of the earth. 



LIFE-ACTIVITIES OF A PLANT 



To one who has never studied botany it may seem that 

 most of the activities named above as characteristic of living 

 animals are absent from living plants; but a careful ex- 

 amination shows that living plants move, breathe, require 

 food, and reproduce, and in still other ways resemble animals 

 in their life-activities. 



24. Living plants have movement. It is true that most 

 plants with which we are familiar are not capable of locomo- 

 tion (i.e., movement from place to place) ; but the same is 

 true of many lower animals. On the other hand, there are 

 many lower plants (to be studied later) which have locomo- 

 tion like that of some lower animals. 



Locomotion in animals is only one phase of their move- 

 ments, and much more impressive are the constant movements 



of internal organs, such as the 

 heart and the lungs. There are 

 many similar cases of plants able 

 to move certain organs, e.g., the 

 Mimosa (" sensitive plant ") 

 moves its leaves and branches 



FIG. 1. The "sensitive plant" when touched (Fig. 1); the Ox- 



(Mimosa). a, expanded leaf; alis, the bean (Fig. 30), and cer- 

 being touched. tain c i overs f o id their leaflets at 



night; the Venus fly-trap (Fig. 

 2) has peculiar leaves able to snap together and catch in- 

 sects ; many plants twine their stems around supports ; and 

 plants bend toward the light when growing near a window. 

 All such cases show that animals have no monopoly of move- 

 ment ; for in addition to cases of plants which have locomotion 



