116 British Uredinee and Ustilaginee. 
with them; then, by simply brushing the water on the 
leaves, you may be pretty sure of successfully infecting 
the plant. Replace the bell-glass, and give it another 
douching outside with the watering-can. If sufficient 
material has been prepared, each alternate barberry may 
be infected in the same manner. The bell-glass need 
not be kept over the infected plants more than two or 
three days. If the weather be very bright, the bell-glasses 
should be shaded by putting a piece of matting or carpet 
over them to prevent the foliage being scorched by the sun. 
In the course of eight or ten days the yellow spots on 
which the spermogonia are produced will appear, and in 
two or three weeks the perfect xcidiospores will be de- 
veloped. It will then be seen that only those barberries to 
which the spores: were applied have the zcidiospores on 
them, while the alternate plants remain free. If an attempt 
be made to infect a plant in the day-time, when the sun’s 
rays are full upon it, it will be found that the water all 
runs off the leaves ; but by operating in the evening in the 
manner directed, the leaves are bedewed with a thin layer 
of moisture, and no difficulty will be found in applying the 
spore-charged water. 
Should it be desired to perform the converse culture— 
the infection of wheat plants with the barberry zcidiospores 
—greater care is necessary to prevent the control plants from 
becoming infected, because the zcidiospores will not diffuse 
themselves in water, and are very readily carried away by 
currents of air. The simplest way is to plant some wheat 
in two flower-pots, and at once to place the pots on two 
plates of water and cover each with a bell-glass. As soon 
as the young wheat plants have made a green leaf, those in 
one of the flower-pots may be infected, using the same 
precautions as are given above. The acidiospores may be 
collected by brushing them into a watch-glass of water 
