THE NEW EARTH 



was just as effective as the imported soil. It is 

 probable, also, that the soil once inoculated 

 always remains so. 



While the difference in the yield at first was 

 not large, the plants bearing tubercles were 

 superior to those not having them, both in seed 

 and fodder. The plan of scattering the inocu- 

 lated soil upon the surface of the ground 

 proved an utter failure. The soil containing 

 the bacteria must come in contact with 

 the seeds. Beans planted with one thousand 

 pounds of Massachusetts soil scattered broad- 

 cast showed an average of only seven tubercles 

 per twenty plants, while, when the beans were 

 put in with drills, with only three hundred and 

 seventy-five pounds of the infected soil per 

 acre, the infected soil coming into contact 

 with the seeds, the tubercles averaged thirty- 

 five per twenty plants. Where the Massachu- 

 setts soil was spread more thickly in the 

 bottom of the drill furrow and the seed dropped 

 upon it, twenty average plants grew five hun- 

 dred and nine tubercles, a single plant bearing 

 seventy-one and another sixty-nine. 



But still more important than all this is the 

 fact that the tubercles upon the roots of the 



38 



