Jul. 842, U. S. Dept. of Agriculture 



Plate I. 



Leaves of Wheat Plants Affected by Tylenchus tritici. 



A, Month-old seedling from the greenhouse, inoculated by placing a few drops of water 

 containing larvse on the seed when planted. Note the abnormal wrinkling of the central 

 leaf. B, Leaf from an infected greenhouse seedling, showing the characteristic wrinkling, 

 rolling, and twisting caused by the nematodes. C, Part of an almost mature field- grown 

 plant the head of which contained many nematode galls. The upper leaf often is found 

 tightly rolled on such plants. 



