Dec, I92I] LEVINE — ^ STUDIES ON PLANT CANCERS 525 
oculated varied widely, the average weight of the roots with crown gall' was 
greater than the average weight of the normal or uninoculated roots in the 
same plot. 
5. Three different types of crown gall were observed in Beta vulgaris, 
namely, the smooth type, the warty type, and a mixed type consisting of 
the warty and smooth types. 
6. The reaction of the beet to crown gall depends upon the health of 
the beet; that is, with any given lot of seeds the extent of the reaction and 
the size of the crown gall depend ultimately upon the condition of the soil 
and upon other environmental factors. 
montefiore hospital, 
New York City 
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