Cir. 76, Bureau of Plant Industry, U. S. Dept. of Agriculture. 



Plate I. 



Fig. 1 .—Nitrogen-Fixing Nodules of Alfalfa. 



Fig. 2.— CROvyN-GALL Tumors of Alfalfa. 



^ 



Fig. 3. -Nitrogen-Fixing Nodules of Crimson Clover. 



^ 



f 



1 



Fig. 4.-CROWN-GALL Tumors of Crimson Clover. 



NITROGEN-FIXING NODULES AND CROWN-GALL 'L'MORS. 



(NiUui-itl size.) 



