Steam Sii:rii.iz.\ti()x on \\'atkk-S(ji.li;li-: Matti:k ix Soils. 269 



soil. At harvest there was Httlc difference between crops in other 

 pots, certain of which had been given an infusion after steaming. 



The effect of the infusion on the growth of the wheat and millet on 

 the sterilized soil was most peculiar. As has been stated, the result 

 of the inoculation was to improve the early growth of the crop; and this 

 was marked, as may be seen from Fig. 72, which shows wheat plants 

 44 days after they were planted in Soil No. 5. Fig. 73, which shows 

 the same plants four weeks later, gives evidence of even better relative 

 growth on the soil to which the infusion was added. As growth pro- 

 ceeded the difference became less marked. In Fig. 74, which shows 

 pots duplicating those represented by the two preceding figures, the 

 plants on the sterilized soil that was not inoculated have caught up 

 with those on the inoculated soil. This photograph was taken about 

 four months after planting. Fig. 75 represents the plants some two 

 months later at which time the effect of the inoculation had been to 

 decrease very noticeably the growth of the plants. Fig. 76 is repro- 

 duced from a photograph of a crop of millet following the wheat on 

 these same pots without any further treatment having been given 

 the soil. The millet was planted a few days after the wheat was 

 removed, and was photographed no days after the seed had been 

 planted. The soil in these pots was sterilized December i, 1908, and 

 this photograph was taken October 4, 1909. The effect in the ten 

 months was most striking. 



A similar experiment with Soil No. 2, which was not continued to 

 include the second crop, did not give such pronounced differences 

 during the growth of the first crop and possibly would have shown 

 correspondingly smaller differences in the second crop. The yields 

 on these soils were as follows: 



Table XI. 



