PLATE i 
Stems of tomato and tobacco from inoculation experiments, showing the relation of 
crowngall development to the size of punctures and to the extent of the water- 
soaked areas surrounding the wounds 1 
A, B, C, D, E.—The relation between the diameter of the inoculating needle and 
the size of the gall. Photographed 25 days after inoculation. The diameters of the 
inoculating needles used, expressed in microns, were as follows: On A, 30; B, 56; 
C, 147; D, 248; and E, 385. Note that the size of the resulting galls increases quite 
consistently with the size of the needle and the extent of the water-soaked area. 
Xn/20. 
F. —Longitudinal section of a tobacco stem showing the flooding of the intercellular 
spaces with liquid after a puncture. The water-soaked area (b) appears as a dark 
region about the puncture (a). X4/5. 
G. —Tomato stem showing water-soaked areas resulting from punctures with iiocu- 
lating leedle (outlined with India ink). Photographed promptly after puncturing 
and making. X9/10. (The stems G to K, inclusive, show the relation of crowngall 
development to the water-soaked areas surrounding the wounds.) 
H. —A stem treated as G, photographed three weeks after inoculation. The ink 
lines (retraced in order to appear distinct) show that the margins of the resulting galls 
coincide approximately with the limits of the original water-soaked area. X9/10. 
I. —A stem that was punctured and, after a half hour, burned in the same place 
with a red-hot needle. No bacteria were applied. It served, therefore, as a control 
on J and K. X9/10. (It appears in I, J, K that galls may develop from water- 
soaked areas in which th* ruptured cells ha\e been destroyed by heat.) 
J. —As I, except that the crown-gall bacteria were applied immediately after the 
punctures were made, that is, a half horn* before the burning. Galls appeared in 
the water-soaked regions that were unaffected by the burning. I and J were pho¬ 
tographed two weeks after the beginning of the experiment. X9/10. 
K. —As J, but photographed three weeks after inoculation. X9/10. 
1 These results are interpreted to indicate that che crowngall bacteria are located in the liquid which 
is released by the wound and which occupies the intercellular spaces about the punctures. 
