122 DISEASES OF GLASSHOUSE PLANTS 
assisted by a film of water on the surface of the plant. 
Unless they gain a speedy admittance the rays of the sun 
and dryness of the atmosphere will soon kill them. 
Frequently bacteria are carried on the mouthpieces or 
suckers of insects, and by these are placed in direct 
contact with wounded tissues, into which they rapidly 
spread. 
Once inside the plant tissues the bacteria feed and 
rapidly multiply, producing millions of new organisms 
in an incredibly short space of time. 
Wilt Disease of the Cucumber 
The symptoms of the bacterial wilt disease of the 
cucumber are very similar to those produced by fungi. 
Plants moderately resistant to the disease, or those in 
very favourable conditions, may wilt during the day and 
recover at night, and such plants are frequently stunted 
in comparison to their healthy neighbours. As a general 
rule, however, cucumbers are so susceptible to the 
disease that death is exceedingly rapid, and usually 
occurs within two or three weeks after the appearance 
of first symptoms. A yellowing of the foliage may 
accompany the wilting, but generally this is not so, the 
leaf-laminz wilting while still green. This takes place 
quite suddenly, and the plant presents a curious appear- 
ance of having its leaf surfaces wilted and hanging limp 
from turgid petioles and stems. The leaves soon wither 
up and die, being followed in this respect by the petioles 
and stems, until the whole plant hangs limp. Frequently 
no destruction of the root is evident, but upon cutting 
across a diseased stem a white bacterial ooze emerges 
from the cut ends of the vascular bundles. This is so 
sticky that if the finger is pressed against the cut surface 
and slowly taken away the bacterial ooze sticks and may 
be drawn out in fine cobweb-like strings. The oozing 
of the bacterial mass is most evident if cut pieces of 
stem are placed with one end in a basin of water under 
