130 AGRICULTURAL AND INDUSTRIAL BACTERIOLOGY 



pressure, for example, when proteins are broken 'down 

 through peptones to amico acids, there is marked increase 

 in osmotic pressure. When starch, which has almost no 

 osmotic pressure, is broken down into dextrins, maltose, and 

 finally to dextrose there is relatively an enormous increase 

 in osmotic pressure. Bacteria when growing in the tissues 

 in the body may bring about changes which increase the 

 osmotic pressure and tend in consequence to abstract water 

 from the tissues. 



Conversely, when simple molecules are combined with the 

 more complex there is a resultant decrease in the osmotic 

 pressure. Certain bacteria polymerize sugars into poly- 

 saccharides, the latter having practically no osmotic pres- 

 sure. 



