THE 
AMERICAN NATURALIST 
VoL. XXVIL Gace 1893. 322 
BACTERIOLOGY IN ITS GENERAL RELATIONS: 
By H. L. Russert. 
Bacteriology, although the youngest member of the biologi- 
cal sisterhood, has developed so rapidly within the past two 
decades, that to-day it may fairly claim for itself an indepen- 
dent Casia. Independent, however, not in sense of isolation 
from other branches of scientifie thought, but as occupying a 
field that is more or less distinct in itself. The scope of this 
subject has already widened to such an extent, and the litera- 
ture grown to be so voluminous, that it is fairly entitled to be 
ranked as a separate branch of biology. This necessity is 
also emphasized by the difference in technique, that separates 
it more or less distinctly from other departments of research. 
It was not until the middle of the present century that the 
affinities of the bacteria were even approximately determined. 
Zoologists first claimed this class of organisms as belonging to 
the animal kingdom, but gradually, as bacterial forms became 
better known, and more fully studied, their plant-like similar- 
ities were detemined. Botanists, for many years contributed 
but little toward a more perfect knowledge of this class, and it 
is the science of medicine that bacteriology must ever regard 
as its foster parent. The establishment of the causal relation 
between these minute forms of organic life and disease, at once 
invested them with increased importance and made them sub- 
1Delivered before the Biological Club of the University of Chicago, Feb’y, 1893. 
57 
