1901] MICROSCOPICAL JOURNAL. 49 
light, but the color of A. Ralfsiz, with exception of that 
on its narrow margin, is only visible with transmitted 
light. 
In this narrow margin the single process or nodule is 
situated ; this I find hasa very finely perforated cap, very 
similar to those of the Aulisci which have been previous- 
ly described. The resolution of this detail is exceeding- 
ly troublesome, and perhaps it is one of the most difficult 
images the microscope, as at present constituted, is capa- 
ble of dealing with.—The Quekett Club. 
The Limitations of Clinical and Microscopical Evidence. 
W. K. JACQUES, M. D., CHICAGO. 
To correctly interpret the phenomena of disease and 
health, one must have a clear conception of the relation- 
ship sustained by pathogenic bacteria in the causation of 
disease. The older bacteriologists, led by the great Rob- 
ert Koch, believed and taught that germs were the cause 
of disease, using the word cause in its scientific sense. 
That is to say, that within the germ are all the elements 
which are manifest in the effect, disease. This was in di- 
rect opposition to the teachingsof Virchow’s cellular path- 
ology. Between these great leaders and their followers, 
has waged a long war, with the gradual evolution of the 
fact that both are partly right. 
Disease is a process brought about by many factors, no 
one of which may be the all sufficient cause,any more than 
the electric spark may be the all sufficient cause of a dy- 
namite explosion. 
The germ is many times the exciting cause, or the last 
factor added to set the disease process in motion. The 
Klebs-Loeffier bacillus,the pneumococci and other micro- ‘ 
organisms may be carried in the mouth of a healthy in- 
dividual for long periods of time without becoming path- 
ogenic, until the individual becomes susceptible through 
lowered vitality and the disease process is set in motion. 
