PLATE-CULTIVAT 



turned down and the temperature^ 

 allowed to fall until the thermometer stands just 

 above 50 C. The water must be maintained at 

 this temperature, and the test-tubes must be in turn 

 rapidly inoculated and poured out upon the glass 

 plates, as already described. Glass plates may 

 also be employed in a much simpler method. The 

 nutrient jelly is liquefied, poured out, and allowed 

 to set. A needle charged with the material to be 

 inoculated is then streaked in lines over the surface 

 of the jelly. This method is of especial value in 

 inoculating different organisms side by side, and 

 watching the effect of one upon the other, or a 

 micro-organism in this way may be sown upon 

 gelatine which has been already altered by the 

 growth of another micro-organism ; the change 

 produced in the gelatine, as in the case of the 

 fluorescing bacillus, extending far beyond the 

 limits of the growth itself (Plate VIII., Fig. 3). 

 Nutrient jelly may also be spread out on steri- 

 lised microscopic slides and inoculated as just 

 described, or cultivations may be made in shallow 

 glass dishes, glass capsules, etc., which must be 

 sterilised on the principles already laid down, and 

 after inoculation placed in damp-chambers for the 

 growths to develop. 



