272 FORMATION OF SLIME OR GUM BY RHIZOBIUM LEGUMINOSARUM, 



During the hydrolysis of the gum, furfural was detected, and the 

 osazones obtained from the neutralised solution consisted of a 

 mixture of glucosazone and galactosazone. From the calculated 

 rotation and the relatively greater quantity of glucosazone in the 

 mixture, the glucose was chiefly, if not entirely, dextrose as in 

 the previous case. 



The gum of the Pea race was dextrorotatory, the specific 

 rotation being [a] D = +31 -7°. During hydrolysis, furfural was 

 detected. The hydrolytic products contained galactose and a 

 glucose. 



The gum of the Bean race was dextrorotatory and yielded 

 dextrorotatory products upon hydrolysis, during which furfural 

 was detected. The sugars consisted of galactose and a glucose. 



The gum of Vibrio denitrificans was rather difficult to clarify > 

 but the solution permitted enough light to pass to show that it 

 was dextrorotatory like the product of its hydrolysis. During 

 the hydrolysis furfural was given off and the neutralised solution 

 yielded, after treatment with phenylhydrazine solution, a mixture 

 of glucosazone and galactosazone. 



With the exception of a difference in the direction of rotation 

 of the gum of the Macrozamia race, the gums were all more or 

 less alike. 



It has been shown that Rhizobium leguminosarum and Vibrio 

 denitrificans, the former of which is supposed to fix ambient 

 nitrogen, the latter is capable of doing exactly the reverse, can 

 assume a similar morphological structure and produce slimes of a 

 similar chemical nature. According to Marshall Ward, the slime 

 is simply the capsule of the micro-organism which has become 

 swollen, the "diffuse-sheath" as he calls it. It is evident then 

 that the formation of bacteroids depends entirely upon the 

 chemical nature of the capsules of the bacteria, and that there is 

 no reason to connect the formation with any fixation of nitrogen, 

 that may occur within the plant. 



The slime which Rhizobium produces has thus as its typical 

 constituent a gum which hydrolyses to a mixture of dextrose and 

 galactose. This peculiar gum may be of great importance to the 



