92 
N. C. AGRICULTURAL EXPERIMENT STATION. 
like threads on the underside of the affected leaves, especially in the 
more moist regions as at the base of the leaves near the stem. This 
character is limited to Sclerotiniose, and is a sure indication of this 
disease. 
Fig. 3 . Sclerotiniose: mycelium growing upon leaves in culture dish. This cotton-like weft 
of mycelium is definitely characteristic. 
In the last stages of the disease, a week or two a£ter the final drop¬ 
ping of the plant, there will be found many small black bodies, varying 
in size from that of a pin head to a grain of corn, in, or upon, or 
under the sick portions of the plant. These too are absolutely char¬ 
acteristic of Sclerotiniose. 
These three characteristics—the dropping, the cotton-like mycelium, 
and the sclerotia—if carefully observed, enable anyone to pronounce 
with certainty as to whether or not a given bed or plant is affected with 
Sclerotiniose. 
History of Sclerotiniose in America. 
The disease characterized by the symptoms indicated above is termed 
sclerotiniose from the fungus Sclerotinia which is its cause. 
Since one of the chief symptoms of Sclerotiniose, the symptom which 
certainly first catches the eye of practical lettuce growers, is a dropping 
