12 



Muscardine in the case of the silk worm, the theory seems 

 plausible that we may in time learn on the other hand, how to 

 suppress injurious insects by fostering the growth of parasitic 

 fungi which would spread infection among them and carry with it 

 disease and death. 



Finally, it must be confessed that the main question at issue is 

 by no means decided, perhaps not seriously affected by the ex- 

 periments and conclusions which I have here recorded. Though 

 the yeast fungus may not be destructive to the insects named, and 

 under the given conditions, it may, nevertheless, be destructive to 

 other ■ insects, or even to these under other conditions, or if the 

 yeast fungus should prove to be wholly worthless and unreliable, 

 it does not follow that there are not other forms which may be 

 successfully employed as insecticides to the very great advantage 

 of our most important national industry. 



