514 
AMERICAN JOURNAL OF BOTANY 
[Vol. 8. 
are relatively small and the leaves few. A considerable number of plants 
in this plot died. Here, also, the figure represents the condition of the plants 
in the plot one nionth after inoculation. An examination at this time of 
the roots of a few plants from plot "E," on good soil, showed that the 
inoculated plants had produced crown galls which were about the size of 
small hickory nuts, while those on the roots of the largest plants in poor 
Fig. 4. A portion of plot "SW" with the garden beet, one month after inoculating 
the root with Bacterium tumefaciens; the soil was unfertilized and had never before been 
cultivated. 
soil, plot '*SW," were barely in evidence or at most had attained a size 
equal to that of a pea. 
On examining the roots of the beets in October, when the entire group 
was harvested, the crown galls on the plants grown in the good soil, plot 
"E," were proportionately very large as compared to those on the roots of 
beets grown in plot '*SW." Often the crown gall surrounded the entire 
upper portion of the root so that the normal contour of the root became 
indistinct. Figure 5 shows some typical roots with crown gall grown in 
good soil (plot "E"). 
The plants grown on poor soil (plot "SW") which were inoculated at 
about the same time as those growing in plot "E" were not only small, 
