GALLS 



389 



form cataplastic plant galls. Galls are due to species of Synchytrium, 

 to the aecidial stage of the rusts on violets, barberries, nettles and buck- 



FiG. 156. — Longitudinal section through red clover rootlet, showing formation 

 of tubercle, a, Rootjhairs; 5, normal root parenchyma; c, vascular tissue; </, infected 

 areas showing infection strands; e, growing cells of tubercle. (Fig. 44, page 95, 

 Schneider, Pharmaceutical Bacteriology, 1912.) 



