62 COMPOSITION OF BACTERIA 



The cell membrane is, therefore, more nearly that of the animal 

 than the plant. The brown color obtained on staining some 

 bacteria with iodin has led observers to believe that they contain 

 glycogen, whereas the blue color with the same reagent is attributed 

 to starch. 



The capsules contain comparatively large quantities of mucin. 

 These are protein-like substances which may be precipitated by 

 alcohol. They give most of the protein reactions and, in addition, 

 when heated with an acid, acquire the property of reducing Fehling's 

 solution, thus showing them to contain a carbohydrate complex in 

 addition to the protein. 



The cytoplasm consists largely of bacterial proteins which appear 

 to be specific in character for any given species. Within this are 

 large quantities of the nucleoproteins, for on hydrolysis large 

 quantities of the purine bases are obtained. Vaughan, Wheeler 

 and Leach conclude that the bacterial cytoplasm contains carbo- 

 hydrates, nuclein bodies, and polymers of mono- and di-amino-acids. 

 They are glyconucleoproteins. Spores differ from the vegetative 

 organism in that they contain but small quantities of water. 



REFERENCES. 



Vaughan: Protein-split Products in Relation to Immunity and Disease. 

 Kendall: Bacteriology General, Pathological, Intestinal. 

 Kruse: Allgemeine Micro biologic. 



