396 BROOKLYN BOTANIC GARDEN MEMOIRS 
In various heteroecious rusts it has been suggested that the aecidial 
host may act as a bridge for races occurring on the uredo and teleuto 
hosts to pass over on to other species normally beyond their range of 
infection. In the case of Pucvinia graminis the aecidial host, Berberis 
vulgaris, is common to all the races specialized on different kinds of 
grasses. In the aecidial stage the difference between the races on the 
gramineous hosts might disappear and the aecidiospores produced on 
the barberry might have a much wider range of infection. 
Several investigators have published data bearing on this point. 
Eriksson (41) has infected the barberry using teleutospores from more 
than fifty different grasses. In some of these cases the aecidiospores 
produced were used to inoculate various gramineous hosts. Some of 
Eriksson’s results may be indicated in the following summary: 
Aecidiospores Sown on 
ew [ole eis wsxlSulegiky S| S| 218s 
Teleutospores from SE Sx eS Sis Sis 8 Rs x8 \8 avs gs s Sle sis s 
SS (SES SISSISS SOIESIS SIS EIS S/S SISSIES 
8| alate Ibs etl vom i Skat 8] s] aS 
NE | A pe a (a | 
AVENAE | | 
AVECNOSSCLLUD nee an 2/2 1/I 0/2/6/2 0/2 
IBTIZOU NOX ae a I/I o/1\1/I o/I 
Bromus arvensis .......... 1/1 |o/I | o/I 
Bromus brachystachys..... L/e \O/a io/1/0/1 O/I 
Bromus madritensts....... 1/1 \1/1 }0/1/1/1 0/1 
Dactylis glomerata ........ 1/T | 
Festuca MYUTUS. 0... ose: 1/I o/1)1/1 o/I 
Festuca tenutflora......... ie «| 0/1 0/1 o/I 
IOClena@ SCLDGE, 32045 rey o/I 0/1 o/1\0/1 
Milium effusum .......... 2/2 o/I 0/1 o/I 
Phalaris canariensis.......| 1/1 G/1|1/1 o/I 
Phleum asperum.......... 1/1 0/1/0/1 o/I 
Vulpia bromoides......... 1/1 |0/1\0/1 o/I 
SECALIS 
Agropyron repens......... 0/1 1/I 1/1\1/1| 0/1 
Bromus secalimus:...:.... o/I 1/1 
Elymus sibiricus.......... \1/I 
Hordeum vulgare.......... 0/2 2/2\1/1 1/2 
MS ECOLCNGETCOLCH Ee te 0/2 2/2\2/2 0/2 
AIRAE 
ATG UOLVICU Seni 1/1 
POAE 
IPOGACOESIA Te ere o/1|1/1 
WOUIGONUDT ESS ay. ee AOL o/1\1/I 1/1\0/1\0/1 
TRITICI | 
Triticum vulgare.......... 1/3 |2/3\1/2 6/7 
In general, the aecidiospores from the barberry are restricted in 
’ The denominator of the fraction indicates the number of tests and the numer- 
ator the number that were successful. 
