CHAPTER I. 



ON SOME OF THE CONDITIONS AFFECTING THE 



LIFE OF PLANTS. 



SECTION A. Respiration. SECTION B. Temperature 



Poisons Electricity. 



SECTION A. Respiration. 



The presence of free oxygen is a necessary condition of 

 the life of all the higher plants. This fact will be more 

 conveniently demonstrated in the chapters on growth and 

 growth-curvatures. The present section is intended as an 

 introduction to the study of the facts without special 

 reference to the importance of respiration. 



(1) Production of C0 2 . 



Take a stoppered jar of about 500 c.c. capacity, fill it 

 to one-third of its height with (in spring) horse-chestnut 

 buds or (in winter) with beans which have been soaked 

 in water for 12 hours and have been afterwards placed in 

 damp cocoa-fibre for 12 hours. Place the jar in a warm 

 room, and after 12 24 hours cautiously open the jar and 

 lower a lighted taper which will be extinguished as it 

 enters the C0 2 produced. 



D. A. 1 



