JOURNAL OF HORTICULTURE AND COTTAGE GARDENER. 
i 
370 
—-- 
[ October 19, 1882. 
Barberry fungus within the Wheat leaf. The minute organs of 
transpiration are small orifices on the under side of the leaves, 
and it is through these open places that plants part from water 
in the form of vapour, and it is through these natural orifices 
that the seeds of the Barberry fungus enter and attack the 
Wheat. 
Mr. Plowright states that he has infected Wheat with Wheat 
Mildew by contact with these spores from the Barberry, and that 
“control” plants not experimented upon remained free from 
the disease. It is not necessary for us to enumerate all his 
experiments, but the general result is, that in ten or twelve days 
after infection the infected Wheat plants sickened with Corn 
Mildew. 
The question now arises, What is Corn Mildew ? Its general 
aspect in the spring is known to every farmer ; the leaves of his 
Wheat are at first covered more or less with pallid spots and 
streaks, and these spots and streaks a little later on become yellow 
and orange. This condition is represented natural size at Q, and 
the fungus bringing about this result is known to botanists as 
of the yellowish powder will be seen as at s. The powder con¬ 
sists of innumerable oval fungus seeds or spores, each borne on 
a slight stalk. As the yellowish spores continue increasing in 
numbers they cause the ulcer to burst, and then the spores fly 
out of the fissure as illustrated. 
As we now have fungus seeds or spores produced of a different 
form and nature from those which arose from the Barberry, let us 
Fig. 61.—WIIEAT MILDEW. 
Uredo linearis. It is said to sometimes result from seeds blown 
from Barberry bushes, the evidence for which we have^already 
discussed. If we magnify one of these disease pustules to the 
same scale as the cups on the Barberry leaf—viz., twenty 
diameters, we shall see them as at n, elongated swollen ulcers 
under the skin of the Wheat leaf; the skin is cracked longitudinally 
down the swollen pustule, and the interior of the ulcer is filled 
with yellowish powder. If a transverse section is cleverly made 
across a pustule and magnified fifty diameters— i.e., to the same 
scale as the more magnified cups of the Barberry leaf, the nature 
enlarge them to the same scale and see how they conduct them¬ 
selves on germination. A group of three of these seeds is seen 
at t, enlarged (like the spores from the Barberry) 600 diameters; 
like the Barberry spores they are yellowish in colour, but instead 
of being round they are oval, instead of being smooth they have 
a granular surface, and instead of being free or in necklace or 
chain fashion, they are now all supported on little footstalks 
as illustrated. When ripe, if these Uredo spores from Wheat are 
kept for a few hours in a damp atmosphere they germinate as at 
V, much in the same style as the spores from the Barberry; the 
