150 



HENRY D. HOOKER, JR. 



Experiment VII. 



Experiment repeated with ten roots of Pisuin iiativu7n 



ORIGINAL LENGTH 



LENGTH AF^ER 8 HOURS 



25 

 29 

 25 

 28 

 31 

 26 

 27 

 26 

 26 

 30 



T' was at 37°C.; T'" at 12°C. In this case all the roots grew beautifully 

 straight. 



Experiment VIII. 



SAME AFTER 7 HODRS 



mm. 



23 

 37 



27 

 28 

 31 



2" registered 40°C. and T'" 12°C. All roots grew straight except number III 

 which was a little bent to one side. 



Experiment IX. 



T' registered 39°C. ; T'" 13°C. All the roots grew straight. 



