Dec. i, 1923 
Morphology of Crowngall 
427 
hydrochloric acid followed by potassium hydroxid, while the latter 
were readily distinguished with polarized light. In some instances 
bodies resembling bacteria were observed in the cut cells as reported by 
Smith (5, p. 253). A few could very easily have escaped from the inter¬ 
cellular spaces at the time the section was made. Little confusion was 
experienced with chondriosomes because the mounting fluid destroyed 
these bodies in a short time. The cells which had been ruptured by the 
inoculating needle and then invaded by bacteria appeared to be dead. 
The puncture was bordered by the discolored walls of such cells. 
SIX-DAY-OLD INOCULATION 
The new gall was easily seen with the unaided eye. Under the micro¬ 
scope the swelling was found to be due to the hypertrophy of the cortical 
cells rather than to much proliferation of tissue. Cell division was 
found to occur to the extent of several new cells in the subepidermal 
region surrounding the original points of bacterial invasion of the inter¬ 
cellular spaces. The proliferation about the intercellular spaces in the 
pith was increased by new walls, which were laid down in the older cells, 
facing the position occupied by the bacteria. The new walls did not 
pass through the middle of the cells but rather cut off smaller portions on 
the side nearest the organism. This phenomenon is still more striking 
in some of the eight- or ten-day-old inoculations (pi . 1, B). So it appears 
that both in the pith and in the cortex small hyperplastic cells, are formed 
within the older cells. The formation of the small cells by division of 
the larger ones is reported by Smith (<?, p. 2) “ < . . the cells have 
not changed places but the change has occurred in situ by conversion 
of the large cells wholly normal into congeries of small cells having all 
the characteristics of tumor cells and visibly surrounded in many cases 
by the stretched wall of the original cell.” 
Observations were made similar to those already mentioned on the 
presence of the bacteria and the changes in the walls surrounding them. 
The cells which were originally invaded by the bacteria appeared collapsed 
against the side of the puncture. Their walls were brown. 
EIGHT-DAY-OLD INOCULATION 
Macroscopically, the gall was conspicuous. With the low power of 
the microscope the regions of hypertrophy and hyperplasia appeared 
enlarged. The small gall cells (pi. 1, D and E) formed a sheath (/) 
about the position of the bacteria (g). In this stage it appears that the 
arrangement of the hyperplastic cells points out the source of the stimulus. 
Outside this sheath in the cortex there was a considerable region of 
hypertrophy where the cells were less and less swollen until the normal 
tissue was reached. In the pith the response was not so great as in the 
cortex, but a distinct sheath of cells was observed. The region of hyper¬ 
trophy was not conspicuous, if present at all. When the sheath of cells 
formed around the intercellular spaces that were invaded in a more or 
less straight line, they produced a cylindrical structure that appeared 
like a strand of tumor tissue extending away from the point of inocula¬ 
tion (pi. 2, A and B). The hyperplastic regions in this stage appeared 
to be collections of more or less irregular cylinders of this nature. It 
seems unlikely that this type of development might have been produced 
by appositional growth in one direction only (Smith 8> p. 34 ). The 
