A SERIOUS LETTUCE DISEASE. 
129 
Iii the other case B. B. Higgins observed a plant of Lamium which 
lay amid a mass of sclerotinized lettuce and had become infected. 
Both of these cases are exceptional. This rarity of infection of plants 
other than lettuce points somewhat strongly to specialization of the 
fungus or to very low resistance by the lettuce plant. 
Sclerotinia libertiana has been reported on many other hosts and 
has been found in North Carolina upon a few others besides lettuce. 
B. B. Higgins brought it into the laboratory on cabbage and a sclero- 
tium disease that appears to be identical with it was sent to the Ex- 
Fig. 28.—Showing healthy leaves and two infected leaves lying upon soil; also an infected pea vine. 
periment Station from Mebane by S. K. Scott upon crimson clover 
and by B. T. Pierce from Charlotte upon alfalfa. According to all 
appearances of the mycelial growth and formation of sclerotia these 
are identical but as the sclerotia were not large enough to produce 
asci and ascospores no comparative data on those structures were 
obtainable. 
Among the hosts upon which the fungus has been reported are the 
following: 
Upon Hemp in Russia, 1868. 
“ Potato in England, 1883. 
“ Bean in Germany, 1886, and in Holland. 
“ Petunia in Germany, 1886. 
