50 



GERMINATION 



that of the earth and that an upward driving force would 

 presumably stimulate upward growth, to the detriment of 

 root production. I was not, however, altogether satisfied 

 and determined to try the effect of difference of polarity, 

 that is to say, using cells of 1 . volt, connecting one with 

 positive to bottom and negative to top of soil, and the other, 

 as a control, with negative to bottom and positive to top. 



For this experiment I took two potatoes, as nearly as 

 possible of equal size and potted them half in and half out 

 of the soil in 6-inch pots ; call them again A and B. 



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/y'g. 23 /^ 24 



Both pots were placed in a dull diffused light in the 

 potting shed and left for thirty days, when the cells were 

 disconnected. Examination was made one hundred and 

 thirty-six days after potting. 



B, that is the one with the upward driving force, showed 

 nine strong shoots, |-inch in thickness and 1-inch 

 to 3 ^-inches high. From the base of the largest of 

 these three other shoots branched out thus : 



^/£.25 



as well as numerous filament-like upper growths. 

 From another shoot there were thirty of these latter 

 and from a third not only seven side growths from 

 |-inch to l|-inches by |-inch, but about twenty fila- 

 mentary ones. The shoots, in fact, all exhibited 



