PLATE 104 
Young shoot of Bryophyllum ccuycinum, showing crowngall stimulus—that is, a pair 
of leaves sending out shoots from their margins as a result of inoculating Bacterium 
tumefaciens (hop strain) in the vicinity of the leaf notches. This pair was plainly 
dwarfed. Inoculated January 13, 1920. Actual height of shoot 24 inches. Some of 
the upper leaflets were knocked off in bringing the plant from the hothouse to the 
laboratory to be photographed, but none of these bore any shoots. There were 12 
shoots on the inoculated leaves. Photographed June 7, 1920. 
48496—21-7 
