286 GLIMPSES IXTO PI.AXT-I.IFE 



and also because the opposite power of assimi- 

 lation is so strong;" that the action of breathing is 

 obscured. In the absence of sunlight, however, 

 it can be observed, as also it ma)' be traced in 

 connection with parts of the plant other than the 

 green leaves. Seeds, for example, during their 

 earlier growth (germination) give off carbon- 

 dioxide freely by respiration. This we can prove 

 for ourselves by taking a large glass jar holding 

 about two or three quarts ; fill this about half full 

 of beans that have been well soaked in water so as 

 to swell them and induce them to commence 

 germination. Close the jar with a tight fitting 

 cork ; after six or seven hours the presence of 

 carbon-dioxide may be easily seen. Have ready 

 a small phial of clear lime water, and with a piece 

 of twine let this down into the jar without spilling 

 its contents ; allow it to remain there some 

 minutes, keeping at the same time the top closed 

 with a handkerchief We shall see that the 

 clear lime water will after a short time become 

 cloudy or milky ; this is due to the carbon- 

 dioxide, liberated by the seeds, forming chalk 

 with the calcium of the lime water, the chalk being 



