244 



Journal of Agricultural Research 



Vol. XV, No. 4 



Table V. — Results of successive transfers of Puccinia graminis phkipratensis to barley 



and oats 



No. 



(Festuca ela- 

 \ tior. 



Original host. 



Do. 



Do. 



{Festuca pra- 

 \ tensis. 



(Phleumpra- 

 \ tense. 



Do. 



Do. 



D ac ty li s 

 ^ glomerata. 



Do 



Do. 



Place of collec- 

 tion. 



Sheridan 

 Wyo. 



....do 



JBellingham, 

 \ Wash. 



Pullman, 

 Wash. 



.do. 



/Ellensburg, 

 1 Wash. 



/Crawford, 

 \ Nebr. 



St. Paul, 

 Minn. 



.do. 



.do. 



Previous 

 history 

 of rust. 



>None . . . . 



..do 



..do 



}..do 



..do 



|..do 



|..do 



jPhpre... 



Noiie 



.do. 



26 ^ 18 2 



B-; 16-B-; 5 



25 5 ^ 



14 16 s „ I „i o 

 0--0- -O- -O- -O O- 



31 17 13 23 9 14 



14 9 „ o ^ o 



B— -Br;; i-B-^-B-; i 



20 14 3 



7 7 T I I 1 o 



B- -B- ; 5-B-; 4-B— B^ -B — B- 



ix 12'^ g'^ ? 6 1 I 



^10 ^o 

 B— -B— ; 2 



31 20' 



b1-°-B^;4-B^ 



44 23' '^ 4 



13 14 8 I 

 ^14 ^10 ^ o ^2 ^o 



o— -o-;-o- -0^-0- 



53 20 20 16 2 



6 "? 4 8 o 

 12 16 7 8 5 



Ph pT= Phleutn pratense. 



In Table V the results of attempts to build up Puccinia graminis 

 phkipratensis from various sources on barley and oats are given. It is 

 possible to maintain the rust for considerable periods of time, both on 

 oats and barley, but the writers have never been able to keep it 

 indefinitely. The number of uredinia became smaller, usually with 

 each successive transfer, and the individual uredinia quite often decreased 

 in size. Eventually so few spores are produced that only one or two 

 leaves can be inoculated and these then fail to become infected. 



