CHAPTER II. 



PREPARATION OF CULTURE MATERIAL. 



ARTIFICIAL cultivations of micro-organisms in suitable 

 nourishing media in the incubator (Fig. i) at temperatures 



FIG. i INCUBATOR, WITH PAGE'S REGULATOR. 



A. Page's Regulator. This consists of a tube filled with mercury, and immersed 

 in the water surrounding the chamber of the incubator. In the upper part of the 

 tube, above the mercurial column,* is a fine open glass tube, having near the lower 



