176. BOTANICAL GAZETTE [SEPTEMBER 
beds containing these plants were generally watered just before 
making the inoculations, to provide a source of moisture for the 
air beneath the covers. When not stated, the height of the plants 
on which bell jars or test tubes were used varied from 8 to 13 inches, 
without straightening up the leaves. 
The wheat seedlings, grown from the rusted seed at Madison, 
Wis., and sectioned for study, were killed and fixed in Flemming’s 
strong solution, imbedded in paraffin, and stained with either 
iron-alum hematoxylin or the triple stain. 
Experimental investigations 
Experiments were begun to show how readily sporidia of P. 
graminis from wheat and native grasses infect the barberry, al- 
though there are very few barberry bushes in North Dakota, so 
few in fact that they could hardly be considered as a source of 
rust epidemics, unless miraculous powers were attributed to the 
wind in causing a widespread and uniform distribution of aecidio- 
spores. In the following experiments small pieces of dead straw, 
which were covered with teleutospores of P. graminis and had lain 
on the ground during the winter, were arranged parallel to each 
other and tied longitudinally on the branches of the barberry 
bushes (Berberis vulgaris), just as the buds were beginning to unfold 
in the spring. 
TABLE I 
INOCULATION EXPERIMENTS WITH TELEUTOSPORES OF Puccinia graminis Pers. 
Number of Date of : Number of 
‘ a : Source of material branches Results 
experiment inoculation Secaukitedl 
Be es April 30, 1906 | Agr. ten.* 5 5 positive 
Oe Sy es April 30, 1906 | Agr. ten 7 I positive 
yO ee , 1906 heat 2 2 positive 
Ge es, April 30, 1906 | Agr. rep 2 2 positive 
$e ey April 30, 1906 | Whea | I I positive 
EE ce ea April 30, 1906 | Hord. jub 2 2 positive 
oo es April 30, 1906 | Ely. tri 2 I positive 
1 Gas Sn eae April 30, 1906 | Wheat | I I posi 
Do Re es , 1906 | 3 3 negative 
* Abbreviations: Agr. ten.=Agropyron te : Age. th te repens; Hord. jub.= 
Hordeum jubatum; Ely. trit.= Elymus paola: oe vul. a Berberis vulga 
