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



Plate V. 



Larv/e of Tylenchus tritici. 



A, Photomicrograph of the root of a wheat seedling growing in a tube of plant-nutrient agar 

 and showing active eellike larvae accumulating about the root tip. The writer was unable 

 to produce infection through the root, however. X 45. B, Masses of milk-white thread- 

 like larvae photographed while actively moving about in a few drops of water after having 

 escaped from the portion of a cut-open flower gall shown near the center of the photograph. 

 X6. 



