5 



spores be eaten by the insect in the case of the fly fungus (Em- 

 ptisa muscm). Huxley says ■} " It has been ascertained that 

 when one of the spores falls on the body of a fly, it begins to 

 germinate and sends out a process which bores its way through 

 the fly's skin ; this having reached the interior cavity of the body, 

 gives off the minute floating corpuscles which are the earliest 

 stages of Empusa. The disease is ' contagious,' because a healthy 

 fly coming in contact with a diseased one from which the spore- 

 bearing filaments 'protrude, is pretty sure to carry off a spore or 

 two. It is ' infectious,' because the spores become scattered 

 about all sorts of matter in the neighborhood of the slain flies." 



In this connection it should be noted that while the insects 

 which infest more or less the plants growing in the laboratory 

 have not been affected in any way by the fungi or their spores, 

 the plants themselves, in some instances, have been seriously 

 injured. On one occasion, recently, some experiments which had 

 been commenced with much care upon Drosera rotundifolia, were 

 brought to a sudden end by a mold which completely overrun 

 and destroyed the plant. That the air of the laboratory should 

 become abundantly charged with spores, would, of course, be 

 expected from the large number of experiments in the growth 

 and propagation of microscopic fungi which at times are being 

 conducted by the members of the classes in mycology. Indeed 

 after a time the spores become so abundant that all apparatus has 

 to be thoroughly cleansed and fumigation by sulphur resorted to 

 in order that the experiments with the fungi themselves should 

 not be defeated. 



The abundance of these spores of many kinds, including those 

 of the house fly fungus, emphasizes the fact that aphides and 

 other plant insects, seem to thrive in the midst of these spores 

 without any diminution of their vigor or power of reproduction. 



Although our whole experience in the cultivation of fungi, as 

 might be inferred from the statements already made, as also 

 nearly all observations made upon fungoid growths in general, 

 indicate that the yeast fungus offers little promise of success as a 

 remedy against obnoxious insects, nevertheless the matter has 

 been deemed of sufficient importance to warrant a considerable 

 amount of labor in the way of experimentation for the purpose 

 of arriving, if possible, at some definite facts bearing directly 



'" Lay Sermons, Addresbcs and Reviews," p. 372. 



