14 
WALTER SPURGEON BEACH 
pecially with the other species of Triticum, and with barley, oats, and rye, 
there was blanching of the inoculated leaves, but this progressed uniformly 
backward from the leaf tips and was not due to a parasite. This reaction 
was also subsequent to the appearance of the irregular yellow spots on the 
leaves of Triticum vulgare. No pycnidia were ever detected upon any 
plant except upon those in which positive infection is recorded. It is 
Setaria 
glauca 
Digitaria 
sanquinalis 
T. vulgare 
Home grown 
spring 
check 
T. dicoccum 1 1 T. compactum 
Lolium 
italicutn 
Brotnus 
secalinus 
0/35 
0/40 
Triticum 
vulgare 
Turkey 
Red 
0/12 
0/40 
T. polonicum 
T. durum 
0/30 
0/60 
Dactylis 
glomerata 
sP/57 
Secale 
cereale 
Festuca 
elatior 
Phleum 
pratense 
Agropyrum 
repens 
Poa 
pratensis 
\ / Avena \ 
' Hordeum \ 
1 1 sativa 1 
vulgare I 
Diagram 4. Infections with Septoria tritici from Triticum vulgare. 
interesting to note that the fungus could not infect hosts closely related to 
Triticum vulgare such as T. durum, T. compactum, and T. dicoccum. If the 
forms of Septoria upon the species of Gramineae listed below are all mor- 
phologically alike, as thej^e is reason to believe, it is evident that Septoria 
tritici consists of more than one, possibly of several, biologic forms. To 
determine the infection-powers of the form on each of these grasses presents 
a profitable field for further experiment. 
Hosts reported for 
Septoria graminum 
Triticum vulgare 
Hordeum vulgare 
Avena sativa 
Secale cerale 
Poa annua 
Hosts reported for 
Septoria tritici 
Triticum vulgare 
Triticum caninum 
Glyceria fluitans 
Brachypodium 
Festuca 
