TYPHOID FEVER. 83 
The injection of mallein would probably supply 
information which would be obtained more easily and 
quickly, and would be more conclusive. 
TYPHOID FEVER. 
Typhoid fever is caused by a bacillus which is 
variable in length, though usually short (about half 
as long as a tubercle bacillus) and thick, its length 
being only about three times its breadth. It does not 
form spores, and it does not stain by Gram’s method. 
It is actively motile; when. a culture of the organism 
in a fluid medium is examined under the microscope 
the bacilli can be seen darting rapidly about in all 
directions. It owes its motility to the possession of a 
large number of long wavy flagella, which can only be 
seen after special and difficult staining processes. 
The bacillus coli communis, the most plentiful organ- 
ism of the intestine in man and animals, bears a very 
close resemblance to the typhoid bacillus, and can only 
be distinguished therefrom by the application of several 
cultural and chemical tests, the performance of which 
takes a considerable amount of time. This renders it 
very difficult to diagnose typhoid fever by methods 
similar to those which are in use for the other diseases 
mentioned, 7.¢., by the demonstration of the specific 
organism. Suppose for instance, that we were to 
attempt to determine the nature of a case of diarrhea 
by a search for the typhoid bacillus in the stools. For 
every typhoid bacillus which we should encounter we 
should find a great many colon bacilli, and we should 
only be able to distinguish the one from the other by 
G2 
