New YorK AGRICULTURAL EXPERIMENT STATION. 109 
fungus under favorable conditions may wilt down and destroy, 
within a day or two, whole boxes of lettuce seedlings. The dis- 
ease is also readily induced by using pure cultures of the fungus 
for inoculation purposes, i 
What is apparently the same fungus has been found several 
times as a disease of maturer lettuce plants. After the presen- 
tation of a preliminary report upon rhizoctonial diseases before 
the Society for Plant Morphology and Physiology in New York, 
December, 1898, we received from Mr. R. E. Smith, Amherst, 
Mass., lettuce plants showing a severe rotting of the leaves. 
There was no doubt about the characters of the fungus, and we 
determined it for Mr. Smith as ‘the Rhizoctonia of lettuce. From 
the characters of the parasitic material, as well as from pure 
cultures, we considered it identical with the damping-off fungus. 
The specimens received showed no rotting of the stem, the 
leaves being the seat of attack. On the older lower leaves the 
leaf blades alone are affected; but the more delicate inner leaves 
succumb entirely, blackening and decaying with the progress of 
the disease. Hyphz! of the fungus occurred scantily over the 
leaf surface, and a short tufted growth might be found on the 
inner side of the petioles. These tufts were brownish-white or 
tawny in color and not so dark as the corresponding growth 
in culture. . 
During the past winter this fungus has also been found by 
Mr. Rolfs on greenhouse lettuce plants at Rochester. 
Again, Atkinson? found a form of the sterile fungus studied 
by him in Alabama, causing damping-off of lettuce seedlings at 
Ithaca. . 
Occurring, then, in such widely separated regions it is very 
probable that it is a fungus very generally distributed. 
1Compare Stone, G. E., and Smith, R. E. The Rotting of Greenhouse 
Lettuce, Bulletin 69, Mass. Agl. Exp. Sta. (Hatch), p.16~-17, 1900. 
*Atkinson, Geo. F. Le. 
