60 LABORATORY BACTERIOLOGY 
spores should be stained red (with the fuchsin) and the rest 
of the organism should be colored blue. 
There is a very satisfactory method recommended by Moller. 
For this and other methods for staining spores, see text-books 
on bacteriology. 
91. Methods for staining Flagella— Johnston and Mack’s 
modified method. Preparation of films. Makea culture on slant 
agar of the organism to be stained and incubate for from 18 to 
24 hours. Prepare a tube with 6 to 8 cc. of sterile water, and 
keep it in the incubator until it is of the same temperature. 
With a sterile platinum loop scrape away some of the growth 
from the agar surface, using care not to remove any of the agar, 
and rinse it off carefully in the tube of water previously pre- 
pared for this purpose. There should be enough to impart to 
the water a faint cloudiness. This should be done in a warm 
room and with considerable care. Replace this tube in the 
incubator and the bacilli will distribute themselves quite evenly 
through the water, though any clumps or masses will settle to 
the bottom. The tube is left in the incubator for from 2 to 3 
days before preparing the films. Place a tray of properly pre- 
pared cover glasses in the incubator to warm ; then, still in the 
warm room, with a platinum loop put a drop or two from the 
tube on each cover (§ 4). Replace the tray in the incubator 
until the water has evaporated, when the films are ready to 
stain. The films require no fixing other than by the mordant. 
With a pipette apply to a film all the mordant the cover glass 
will hold, allow it to act 2 or 3 minutes without heating, and 
rinse thoroughly in clean water; apply the stain in the same 
manner, allow it to act 2 or 3 minutes without heating, rinse 
well, and examine in water, or dry and mount in balsam. 
All these solutions should be freshly prepared. Consider- 
able care in washing after the mordant will be well repaid, as 
it insures a cleaner background. 
Around the edge where the drop was applied to the cover 
glassa heavy line of bacteria will be found, and if the right amount 
