CONTENTS. 



Introduction . 



The point of view 



The plants studied 



Meteorology 

 Methods 



Transpiration 



Stomatal action . 



Effect of caustic potash upon stomata 



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Part I. 



movement to sudden 



chang 



es in illumi 



Transpiration and stomatal movement 



Normal daily periodicity 



Responses in transpiration and stomatal 

 nation .... 



Discussion ..... 



Summary ..... 

 Induced rhythm in transpiration 

 Induced rhythm in stomatal movement 

 Closure of stomata during wilting 



Selected experiments 

 Relative humidity and stomatal movement 



Relative humidity — its influence upon the condition of stomata 



Part II. 



Physiology of stomata, with special reference to the metabolism of guard-cells 

 Normal diurnal changes in contents of guard-cells . 

 Verbena ciliata ...... 



Stomatal movement ..... 



Oil 



Fouquieria splendens .... 



Variation in the starch content of the guard-cells 

 Normal stomatal movement .... 



Summary ....... 



Relation of stomata to certain parts of the spectrum, to darkness, and to air 

 of carbon dioxid .... 



Method ...... 



The red and blue regions of the spectrum 

 Red light ..... 



Blue light 



Darkness . . ... 



Summary for Verbena 

 Additional experiments . 

 Experiments with air free of carbon dioxid 

 Beginning at sunrise ... 

 Experiments commencing at time of minimum starch content of guard 

 Discussion and conclusions . 

 General summary .... 

 Transpiration and stomatal movement 

 Induced rhythm in transpiration . 

 Induced rhythm in stomatal movement 

 Wilting . . . . 



Physiology of the guard-cells 

 Bibliography ..... 



devoid 



cells 



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