24 



A COMPARISON OF DIFFERENT KINDS OF CURRENT. 

 TABLES XII.— XVII. 



In these experiments the seeds were treated with three forms of 

 current. As in the foregoing tables, twenty-five seeiis were used for 

 eacli form of treatment, also the method of stimulation, the germi- 

 nation, the temperature and number of cells used were the same as 

 previously described under Tables I. — IV., each lot of seeds being 

 stimulated for a period of two minutes. 



The first series of figures in each table represent the normal or 

 untreated lots, the second represent the result of treating the seeds 

 with an interrupted induced current from the Du Bois-Reymond 

 , coil, the secondary coil being seven centimeters from the primary, 

 the distance which previous experiments had shown to give the 

 optimum effect. In the third series the treatment was also with an 

 interrupted induced current, the secondary coil as in the above case, 

 but with this treatment the Wagner hammer was not connected, the 

 wires being attached directly to the primary coil, and interruptions 

 were made by making and breaking the circuit ten times. In the 

 fourth form of treatment a direct current was used which was passed 

 through the seeds directly from the battery. 



In Tables XV. — XVII. the experiment was continued for 96 hours 

 and the average lengths of the hypocotyls taken. 



TABLE XII. 



Effect of different kinds of current upon the germination and growth 

 of the radicles of 



WHITE MUSTARD (bRASSICA ALBA) , 



