y a b c 



Fig. 4. 



Young tomato plants grown in conditions similar to those of Fig. 3, but showing 



acceleration 

 treated soil. 



both the heated soils. 

 Soil heated to 200° F. 



a. Soil heated to 120 0 F. b. Un- 



ci b c 



Fig. 5. 



Roois of tomato plants grown in {a) Tomato "sick' J soil heated to 130° F. 

 (b) some of the same lot of soil untreated, (<:) the same soil heated to 200° F. 



