362 READINGS IN EVOLUTION, GENETICS, AND EUGENICS 
stunted and otherwise abnormal plants, some of which bred true for 
several generations. The work was not followed long enough to 
determine whether the change was one involving a rather prolonged 
induction or was a permanent mutation.—Eb.] 
Fic. 61.—Two plants of Onagra biennis, showing the effect of injections of 
zinc suiphate into the ovule. A, normal; B, the modified plant, which arose from 
seeds that had been modified by zinc sulphate. (From MacDougal.) 
