PLATE 52 



A. — Sweet potatoes showing the typical pox spots and cracking previous to the 

 falling out of affected tissue. 



B. — Top row: Sweet potatoes showing the large pits formed as a result of a heavy 

 infection, and later by the falling out of the pox spots. Bottom row: Sweet potatoes 

 showing the constricted effect and uneven growth of the root as a result of early in- 

 fection. 



49388°— 18 2 



