; 



202 



AMERICAN JOURNAL OF BOTANY 



[Vol. 9, 



TABLE 2 

 (The designations "screening wheat," "smutted wheat," etc., are the millers' terms) 



As the table shows, the rust appeared simultaneously on all the plots of 

 wheat and barley respectively. It appeared at the same time on a resistant 

 variety such as the Macaroni wheat and on a susceptible variety such as 

 Rupert's Giant; on plants grown from seed coming from North Dakota 

 and on plants grown from seed coming from Maryland; on plants from 

 good, plump seed and on plants grown from seed rejected by the miller, 

 such as the "rusted wheat" and the "screening wheat" seed. Evidently 

 the nature and first appearance of the rust were determined by local environ- 

 mental conditions, and variety, age, source, and condition of the seed played 

 a subordinate role at least in this particular case. It is also to be noted 

 that the rust appeared at different times on the different cereals except in 



