BY R. GRBIG-SMITH. 273 



plant if the carbohydrate which is contained in the nucleoproteid 

 molecule of the plant cells is of the same or an allied nature. 

 According to Kossel, the carbohydrate of certain nucleoproteids 

 can be hydrolysed to a glucose and a pentose.* Galactose, 

 although it is not a pentose, might be mistaken for one if incom- 

 pletely investigated, and I have obtained, from Dematium pullu- 

 lans, a carbohydrate which was derived from the nucleoproteid 

 of the mould and which hydrolysed to galactose and a glucose. 

 The observation that the slime and the cells of Hhizobium stain 

 much more deeply when phosphates are contained in the medium 

 upon which the slime is produced than when they are absent may 

 have some bearing upon this question in view of the fact that 

 phosphoric acid is a typical constituent of the nucleoproteid 

 molecule. There is the probability that the plant is capable of 

 utilising the bacterial slime to build up its nucleoprotein for 

 which it appears to be peculiarly adapted. If such be the case 

 the cells of the root in the proximity of the bacteria will be 

 better nourished than the cells of the localities to which the slime 

 may be transported, and there will be a greater formation of 

 nucleoproteid, protoplasm and tissue generally. Thus will the 

 nodule be formed, not because of the irritation by a parasitic 

 bacterium as some authors consider, but because of the assistance 

 given to the synthetic elaboration of at least one important 

 constituent by a symbiont. We thus return to the older and 

 original idea that there is a symbiosis between host and bacte- 

 rium, but the symbiosis relates to the alteration of carbohydrate 

 instead of to the fixation of nitrogen. 



While the races of Hhizobium obtained from the nodules of the 

 Lupin were capable of producing a luxuriant growth of slime 

 immediately after isolation, the bacteria isolated from the stems 

 of the same plants produced none. The location of the micro- 

 organisms in the plant is clearly of considerable importance so 

 far as the production of slime is concerned. In the feebly acid 

 nodule the bacterium can form slime, a thing which it cannot do 



* Wohlgemuth obtained xylose and no other sugar from liver nucleoproteid 

 (Biochem. Centrlb. i. 464). 



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