1897 | “ BACTERIOSIS” OF CARNATIONS 205 
teriosis,’’ excepting the presence of bacteria, is produced by the 
puncture of aphides, as was repeatedly proved by the coloniza- 
tion of these insects on the plants. 
6. That the aphides alone are responsible for the trouble is 
shown by the fact that the injuries produced are not accom- 
panied in the earlier stages by fungi or bacteria. The aphides, 
therefore, can not be looked upon as carriers of any fungus or 
germ. 
7. Injuries similar in many respects to those produced by 
aphides also result from the attacks of thrips, an insect nearly 
always present on carnations under glass, although generally 
overlooked by growers. 
8. The carnation is a plant readily influenced by the con- 
ditions under which it is grown, and asa result the reaction to 
the injury of the aphides and the susceptibility to their attacks 
not only vary with varieties, but with individuals of the same 
variety. Plants, therefore, grown under improper conditions will 
show more of the characteristic injuries from a given number 
of aphis punctures than those where allthe conditions have been 
favorable for growth. 
9. Proper selection and propagation of stock; furnishing 
soil, moisture, light, and air best adapted to healthy and vigor- 
ous growth; and keeping down to a minimum the number of 
aphides and thrips will enable the grower to successfully combat 
the disease. 
DIVISION OF VEGETABLE PHYSIOLOGY AND PATHOLOGY, 
DEPARTMENT OF AGRICULTURE. 
