73 
itself or for fixing upon the microbe a greater power for infection or a 
cooperation of both upon the same basis. Either cause would result 
in attaining the greatest infection. 
In preparing pure cultures the records show that in the process of 
isolating the desired germs from the dying host, at least one and some 
times two additional well-defined germs were obtained, which were 
either associated or coincident with the disease. It is an interesting 
and important study to determine what are the relations of these germs 
to each other, either preceding or during the progress of the disease. 
Primarily the results of the observations and experiments develop 
the following facts: 
(1) That the germs experimented with are only facultative in their 
relation to the Boll Worm. 
(2) That, as such, in the manner cultivated and in the condition 
applied, they fail to produce results which are of primary economic 
importance. 
(3) That such failure has no primary bearing upon the availability of 
strictly parasitic organisms to assist in producing infection by artificial 
methods and obtaining practical economic results. 
Secondarily they rather definitely suggest the following general prop- 
ositions : 
(1) The importance of giving the most exhaustive study to ascertain 
what environments, as to both the insect and the germ, are favorable 
or unfavorable to the infection and development of disease among in- 
sects. 
(2) The importance of first determining the biological character of 
the organism, /'. e., whether truly parasitic or only facultatively so. 
(3) The determination of the first and second specifies to a great ex- 
tent the further method of procedure, and the basis of experimenta- 
tion. 
(4) The importance of the three preceding considerations demon- 
strates the folly of attempting to obtain practical results by pure culti- 
vations and artificial disseminations, purely as such. 
(5) That making the attainment of practical results the primary ba- 
sis of such investigations is a mistake, and an obstacle to real progress 
in their final attainment. This suggests that — 
(6) The biological and physiological properties of the germs, together 
with their environments, should first be studied and determined upon 
a purely scientific basis, without regard primarily to the attainment of 
practical results, 
