172 
PRINCIPLES OP BACTERIOLOGY 
clays: death was inevitable; during an epidemic, mourn¬ 
ing crepe would be hung out on one house after another, 
an eloquent and silent witness of the dreadful scourge. 
Today a death from diphtheria is a scarlet spot on a 
physician’s escutcheon, there is absolutely no excuse for 
death from diphtheria today, for, unlike the tetanus anti¬ 
toxin serum which is a much better prevention than a 
cure, the diphtheria serum is an extremely efficient cure, 
as well as preventive; the earlier the administration of 
the serum is begun the better the results. 
IX. Summary of Important Characteristics 
A slender Gram-positive bacillus, usually club-shaped, 
presenting when stained, a beaded appearance, growing 
in beef blood serum in small, glistening, grayish colonies, 
nonmotile, causes diphtheria; possesses an affinity for 
mucous membranes, produces an exotoxin, the body re¬ 
acting by the production of antitoxin. Prevented and 
cured by the antitoxin serum. The pseudodiphtheria 
bacillus (Hoffmann’s bacillus) is shorter and thicker, the 
beads or bands in stained preparations seldom exceed 
two or three. It grows more abundantly and colonies are 
whiter than those of the diphtheria bacilli. 
