STUDIES ON PLANT CANCERS III. THE NATURE OF THE 
SOIL AS A DETERMINING FACTOR IN THE HEALTH 
OF THE BEET, BETA VULGARIS, AND ITS 
RELATION TO THE SIZE AND WEIGHT 
OF IHE CROWN GALL PRODUCED 
BY INOCULATION WITH BAC- 
TERIUM TUMEFACIENSi 
Michael Levine 
(Received for publication April i6, 192 1) 
Little is known concerning either the effect on the size and the weight 
of beets, either spontaneously or artificially infected with crown gall, or 
the effect of the general vigor of the plant on its susceptibility to infection. 
Many problems of practical and theoretical importance along these lines 
remain to be solved. Among them are: (i) a more accurate evaluation of 
the effects of the crown-gall disease upon the final size of the infected beet 
and hence on the beet crop; (2) the cause of the greater susceptibility of 
the sugar beet as compared with other races to the crown-gall organism; 
(3) the breeding of beets to obtain strains immune to crown-gall infection 
and yet retaining the desirable marketable qualities; (4) the cytological 
difference between crown gall and "tuberculosis" of beets and the relation 
of the former to animal cancer; (5) the relation of the soil to the health of 
the beet and to the size of the crown gall that it will harbor when inoculated 
with Bacterium tumefaciens. 
Up to the present very little evidence has been advanced by animal 
pathologists to show any definite relation between the physical condition 
and the virulence of cancer once it is started. 
The purpose of this paper is to present some data on the last of the 
questions noted above; namely, the relation of the health of the beet to 
the size of the crown gall resulting from infection. Since the term " health " 
has but a relative meaning, we shall measure health in this case in terms 
of size and weight, the matters most important to the beet grower and 
without doubt fair indices of the vigor and normality of the beet plant. 
Inasmuch as crown gall is analogous to animal cancer, as Smith (191 1, 
1912), Magnus (1918), Levine (1919, 1920), Levin and Levine (1920), and 
Jensen (191 8) have pointed out, these results also have a bearing on the 
general question of feeding in cancer and a more specific relation to the 
question of the relation of general vigor and vitality to susceptibility. 
■ The older literature concerning the crown gall of beets is too well known 
^ From the Department of Cancer Research of Monte fiore Hospital, Dr. I. Levin, Chief. 
507 
