PLATE XC 



Potatoes affected with potato leak: 



Fig. i, 2. — Natural infection from fork wound; photographed by Dr. W. A. Orton. 

 Fig. 3. — Rot produced by inoculation with Pythium debar yanum. 

 Fig. 4. — Rot produced by inoculation with Rhizopus nigricans. Inoculation made 

 by Mrs. Tillotson. 



(64c) 



