66 THE AMERICAN MONTHLY [Feb 
« 
as he would children from scarlet fever. In the diagno- 
sis of malaria, the assistance of the microscope should not 
be ignored, but in order to appreciate its value, the life 
cycle of the plasmodium, its various forms and all the con- 
ditions under which it may be found, as well as the vari- 
ous forms of the disease. in which it is absent, must be un- 
derstood. The physician should keep pace with the work 
of the bacteriologist in order to properly value micro- 
scopic evidence. ) 
When the Widal test for aiiteits fever came out, we 
were amazed at the accuracy with which it confirmed the 
diagnosis of typhoid fever. Extended knowledge has de- 
monstrated that it is not infallible.. Allowing that in a 
small per cent of cases the reaction is not present, it is 
by far the most reliable evidence we have in typhoid di- 
agnosis at the present time. It is to be hoped that fur- 
ther investigation will determine when the reaction is not 
reliable. — 
There is a tendency among those physicians who have 
not had a bacteriological training, to under-estimate the 
value of microscopical diagnosis. 
Influenced by the teaching that the germ is the all suf- 
ficient cause of disease,the bacteriologists in the past have 
claimed too much. To them the germ was the disease. 
Now that the bacteriologists have had to recede from this 
position, the doctor who does not use the microscope, be- 
lieves that it weakens all microscopical evidence. This is 
not true. Microscopical evidence is of more value than 
ever before, if the physician has the knowledge to appre- 
ciate it. The fact that we have a pseudo-typhoid, a pseudo- 
diphtheria and possibly a pseudo-tubercular bacillus which 
causes the bacteriologists to hesitate, only emphasizes the 
necessity of the physician being a closer student of the 
problem of environment; of the germ which causes viru- 
lence, and environment of the patient which causes sus- 
ceptibility. In a germ disease, there is a battle between 
