Cir. 52, Bureau of Plant Industry, U. S. Dept. of Agriculture. 



Plate II. 



Resting Spores of Wart Disease. 

 Section thrDUtrli n siiimII tulicrrlc shiiwiiig sporangia. (After Gtissow.) 



Tuber Showing Warty Excrescences. 



(From Journal ol Hoard of .VKrioultiire, .lanii.iry. I'.IOD.) 



