90 LABORATORY BACTERIOLOGY 
EXERCISE XXXV 
BACILLUS TETANI 
137. The bacilliof tetanus or their spores occur in nature 
as common inhabitants of the soil —at least they are found in 
the soil in certain localities. They are believed to be more 
numerous in certain places where manure has been thrown in 
abundance. J. ¢e¢anz is anaérobic and consequently must be 
cultivated according to methods necessary for such bacteria 
(§§ 1385, 136). In its effect upon the animal body it remains 
at the point of inoculation, the disease being produced by the 
toxin elaborated by the bacilli. 
138. Work for this exercise. Carefully examine the 4 cul- 
tures of tetanus bacilli made in the last exercise and describe 
their appearance. 
Make a cover-glass preparation from the liquid cultures 
and stain them with carbol fuchsin. Examine them micro- 
scopically and describe their appearance. Make a drawing of 
a few bacilli magnified 1000 diameters. Keep these cultures 
until the next exercise, when they should be reéxamined, 
sterilized, and rejected. 
Expectorate into a watch glass which has been wiped with 
a cloth moistened in a 5% solution of carbolic acid. From 
this sputum inoculate a tube of bouillon and one of slant agar, 
and make a series of 2 agar and one of 2 gelatin plate cul- 
tures. Use a small loopful of sputum for each tube culture 
and the same quantity for the first tube in the plate series. 
The saliva from a horse or cow may be collected and substi- 
tuted for human sputum. 
139. Metliod of isolating tetanus bacilli. Tetanus bacilli 
rarely extend beyond the place of inoculation into the body 
of the infected individual (man or lower animal). In the 
local lesion there are almost always other bacteria, so that 
