PLATE 70 
Plasmodiophora brassicae: 
A. —A portion of a longitudinal section through the stem of a young cabbage plant. 
The dark bodies represent plasmodia; host-cell contents are not shown. At this 
stage only the cambial region is infected. X193. 
B. —What is believed to be a very early stage of cell-wall penetration. The 
plasmodium is closely applied to the cell wall, which seems to be softening and is 
bending. 
C. —An early stage in passage through a cell wall. An opening has been made 
in the cell wall through which the plasmodium is beginning to pass. 
D. —A little later stage than that shown in C. Here the plasmodium has started 
to pass through the wall, but has not yet penetrated the protoplast of the new host 
cell. 
E. F.—Still later stages in the passage through cell walls. 
G. —Interesting because a nucleus is passing through the opening in the wall. 
H. —A case in which the opening made in the cell wall is unusually large. 
I. —Plasmodium passing through the end of a cell in the region of the cambium. 
J. —A case in which plasmolysis of the host cells seems to have broken a migrating 
plasmodium into two parts. 
K. —An ameba taken from a cambium cell. 
L. M.—Two small plasmodia that were found in cambium cells far from the point 
of original penetration. 
N.—Infected cambium cell. The host nucleus is in process of division. X836. 
