1896.] The Bacterial Diseases of Plants : 799 
foliar and floral organs. The earliest symptom of disease in the 
bulb consists on cross-section, of yellow dots, visible here and 
there in the interior of the scales or, on longitudinal section, of 
yellow lines which frequently extend into the plateau. From 
these spots, a mucilage swarming with bacteria can be obtained 
in drops by squeezing the scales or simply by exposing the cut 
bulb to the air. Sometimes the whole interior of the scale, or all 
of its inner or outer part, degenerates into a mass of yellow 
slime. Ifthe attack is rapid, the plateau is soon invaded and 
the bulb rots in the ground during the fall or winter. If the 
progress of the disease is slow, and this is usually the case, the 
bulb sends up leaves and blossoms the following spring in the 
ordinary manner. At this time or afterwards there are distinct 
signs of the disease. In many cases the leaves turn yellow in 
lines parallel to the longer axis of the leaf. These lines be- 
gin at the base of the leaf and proceeding upward become less 
and less visible until they entirely disappear. In the interior 
of the leaf under these yellow stripes the bacterial slime is 
abundant and on the lower parts of the leaf it frequently finds 
its way to the surface, ruptures the epidermis and escapes. In 
such plants the bulb is always badly diseased, especially the 
outer scales which are the basal portion of the leaves of the 
previous year, and this, taken in connection with the fact that 
the bulbs are entirely sound in most cases where the symptoms 
are only visible at the apex of the leaf, renders it very prob- 
able that the latter is to be regarded as the first stage of the 
disease and the former as a later stage, supervening the second 
year. Another symptom, sometimes observed the second 
year, is unequal growth, i. e., a distinct curving over of the 
foliage toward that side of the plateau which has perished or 
is no longer capable of furnishing the proper supply of water 
and nutrient substances, the curvature being, of course, due to 
the one-sided growth. Asa rule, diseased bulbs do not pro- 
duce many bulblets, and not all of the latter are always diseased. 
If planted out, those which are diseased show signs of the mal- 
ady in the young plants after a longer or shorter period. The 
leaves turn yellow, become flabby and droop, or show the 
characteristic longitudinal rifts in the epidermis. When such 
