PLATE 38 



A. — Inoculated and uninoculated stems of same potato plant. Stem at right 

 shattered by F. oxysporum. 



B.— Potato plant (control), showing method of inoculating with wedge of melilotus 

 stem. 



C. — Seed-piece rot in field. The yoimg potato plant has not yet been attacked. 



D. — Potato plant naturally infected by F. oxysporum in the field. 



