BY henry TRYON. 
59 
111 introducing the subject of fungus parasites, mention was 
made of the diseases in silkworms due to bacteiia, or the lo\sest 
■class of these organisms, and it may be remai’ked in conclusion 
that bacteria seem equally available with, if not more so t lan, 
these higher forms as aids in contending with insect pests o 
vegetation. Micrococcus occasioning a virulent affection in le 
cabbage white butterfly of Europe and America has been on^ 
since isolated, but investigations with a view to determii e 
efficacy for the purpose mentioned have scarcely procee e 
yet beyond the experimental stage, and at the - ^ ° 
Brefeld better results have attended the employment o t e 
coiiidial form of the Empusa peculiar to the caterpillar o 
insect. Perhaps, however, the most recent . 
direction is that conducted by Mr. F. W. Malley Assrs ant 
Entomologist to the United States Department of ’ 
with a view to discover whether the germs often 
the notorious “ Boll AVorm ’’-Heliothris armiger^a 
insect, might not he utilised as a so-called reme ^ u 
yet his investigations have not led to any very prac ^ 
but amongst other conclusions at which he arrived, 
that from production by artificial means of ^ " “”in 
germ in one species of insect, it did not to 
all cases the same germ could in like manner 
originate a disease in a closely related species, mu 
more distantly related. In the case of .actor a of Bus Boll 
w«,„, to »ha, lu. ' iHlf only “■> 
that their parasitism m relation to g,,bstaiices 
that they were otherwise saprophytic, or i for arriving at 
a successful issue, it was necessary m faculta- 
with a f 'environment which 
S^rrrp^dt^^g disease. The ^^i-t 1 ^. 
perhaps been pursued tar enough thjs evem It P 
sufficient has been stated to show that the 
,of insects is a matter not altogether devoid of mterest. 
