1050 The American Naturalist. [December, 
BACTERIOLOGY IN ITS GENERAL RELATIONS" 
* 
By H. L. RussELr. 
(Continued. from page 859.) 
Quite naturally, the practical application of bacterial re- 
search has been primarily directed along the lines of medi- 
cine and the industrial activities. In any new branch of sci- 
entifie progress, this is almost invariably the case. Our inter- 
est in the subject is largely measured by what it is worth to 
us, and in proportion as it fills this function do we esti- 
mate the importance of its study. "The results that have 
already been accomplished in bacteriology have not however 
been entirely confined to the applied side of the subject. The 
cause of pure science has also been greatly advanced in various 
ways. The correlation of any branch of science with allied 
subjects is to-day so intimate that any discovery in one, often 
furnishes valuable suggestions in kindred lines of research. 
It is in this light that we may consider the effect that bacteri- 
ology has had upon the greater subject of biology, taken in 
the pure not the applied sense, and if possible point out some 
of the lines which seem to promise a rich fruitage from a gen- 
eral biological standpoint. It can hardly be expected that so 
young a member of the biological family could as yet have 
contributed much to the common fund that all its workers are 
striving to accumulate, yet it may with justice be said that the 
circle of its influence has widened much beyond its own par- 
tieular sphere. Perhaps the most valuable of the contribu- 
tions to its sister branches has been in its technique. This 
influence has been most strongly marked in the closely related 
departments of botany. The excessive minuteness of bacte- 
rial forms and the ubiquity with which these organisms are 
distributed made it absolutely necessary that some reliable 
means of pure cultures should be introduced before much real 
advance could be made in this subject. In bacteriology ; this 
!De'ivered before the Biological Club of the University of Chicago, Feb'y, 1893. 
