BACTERIA IN THE INDUSTRIES. 



97 



is already well supplied with rhizobia or root tubercle bacteria, as soil would 

 naturally be if the leguminous plants under consideration had been grown 

 in it for one or more seasons, nitragin would in all probability be-oUittle or 

 no value. In any case, the anticipated results have not been fully realized, 

 and nitragin is withdrawn from the market, and is no longer manufactured. 



A second and later improvement in the method of inoculating seeds with 

 root tubercle bacteria (Rhizobia) is given by Hartleb in the specifications 

 forming part of letters patent No. 674,765, granted May 21, 1901, at Wash- 

 ington, D. C. Although not so stated in the specifications, it is evident that 













i 



o 



I 



FIG. 46. Motile forms of 

 Rhizobium mutabile as they ap- 

 pear in fresh cultures. They are 

 very small, 1/2 to 2/3 p in length. 



FIG. 47. Non-motile matured forms of R. 

 mutabile as they appear in mature sweet clover 

 root nodules. Most of them show the forked 

 ends. This may be considered the normal form 

 of this organism. 



the Hartleb process is a method for applying pure rhizobia cultures to seed 

 of leguminous plants. Whether the method offers any advantages over 

 the method of Nobbe and Hiltner is questionable. In any case it would 

 prove practically advantageous only under the conditions referred to under 

 the discussion of nitragin. Although the method has been freely discussed 

 and experimented upon in Germany, the fertilizer is no longer on the market. 

 There is on the market a third patented germ or microbe soil fertilizer of 

 German origin, known as "alinit." It consists essentially of a pure culture 

 of the soil bacillus known as Bacillus ellenbachiensis alpha or Bacillus ellen- 

 bachiensis Caron. The germ was first brought to the attention of the agri- 

 culturists by Caron, a land owner of Germany, who first isolated it and 

 called attention to the fact that it had the power of chemically binding the 

 free nitrogen of the air. The microbe is said to be closely allied to B. mega- 

 7 



