CLOVER CULTURE. 143 



na:% : . i the experience of many others similarly situated. 

 Until we became acquainted with these investigations we had 

 despaired of finding" the solution of the mystery. It explains, 

 also, why occasional plants flourish, especially on portions of 

 the field where the wild legumes grew. If allowed to remain 

 and mature seed, the clover gradually spreads all over the 

 field, securing- in time a perfect stand. As no subsequent 

 trouble was found in seeding these fields, there can be but 

 one conclusion, viz., that the bacteria were present only in 

 such spots in "the field as had grown wild legumes, and that 

 they multiplied readily and extended all over the field. We 

 might state that recent investigations in Germany have shown 

 that it is necessary to inoculate or leaven certain fields or 

 portions of fields with the microbe of lupines, a leguminous, 

 plant. The readiness with which clover grows on gravelly 

 points on which nothing but prairie grass ever grew, when 

 covered with manure from cattle, and especially horses that 

 had been fed on clover hay, suggests that inoculation with 

 the microbe is fully as essential as the sowing of clover seed. 

 We have felt that it was due to the reader, before closing 

 this volume, to state briefly the facts contained in this chap- 

 ter, which have been established by the most rigid scientific 

 investigation, in order that they may see that in assuming- in 

 almost every chapter of this work that clover is not dependent 

 upon the nitrogen of the soil for its growth, we are making 

 no bald, unsupported assumption, but one that has been de- 

 monstrated with almost mathematical precision, and which is 

 now held by scientific men in all countries where science has 

 attempted to aid the farmer in his work. 



