442 G. p. PLAISANCE AND B. W. HAMMER 



to the type of change resulting in the formation of mannitol 

 from fructose. The rod-shaped lactic acid organisms constitute 

 a group that is present in silage in enormous numbers (Hunter 

 and Bushnell, 1916; Sherman, 1916) and while many of these 

 do not produce mannitol it seems probable that mannitol- 

 producing forms may be expected among them. 



CONCLUSIONS 



1. The production of mannitol in silage is very evidently 

 due to bacterial action. 



2. Mannitol-producing organisms were readily isolated from 

 silage, provided it had been ensiled recently. They were also 

 secured from a sample of fermenting corn juice. 



3. In liquids, more mannitol was produced when they were 

 flooded with oil than when they were not. 



4. Mannitol was produced, by the organisms isolated, in 

 the juice of cabbage and in silage made from corn, sunflowers, 

 cane or dandelions, but not in the juice of carrots, beets, or 

 apples. Fructose, or materials giving fructose on hydrolysis, such 

 as sucrose or inulin, also yielded mannitol when added to stover 

 before sterilization; it is probable that the hydrolysis was due to 

 the heating and the acid present and cannot be accomplished 

 by the organisms although there may be variations among the 

 organisms in this respect. Glycerol, galactose, glucose, maltose, 

 lactose and starch did not yield mannitol when added to stover 

 before sterilization while honey gave large amounts. 



5. The mannitol-producing organisms were found to be pre- 

 sent in soil from a farm yard and in milk. 



6. The per cent of mannitol produced in different materials 

 varied widely, due undoubtedly to a large extent to variations 

 in the types and amounts of sugar present. 



7. With the only organism that was tried, the production 

 of mannitol was accompanied or followed by its partial 

 destruction. 



8. The organisms producing the mannitol in silage cannot 

 be considered to be of one type. 



