118 
[By the courtesy of the author, and of the proprietor of The Gardeners’ Chronicle, 
we are enabled to introduce here the following results of further researches 
upon this subject by Mr. PLowrkiGcut in the year 1882. ] 
THE CONNECTION OF WHEAT MILDEW (Puccinia 
Graminis, Pers.), WITH THE BARBERRY ASCIDIUM 
(42. Berberidis, Gmel.). 
By Mr. C. B. Prowrient, M.R.C.S, 
[Contributed in 1882. ] 
ON THE CONNECTION OF THE WHEAT MILDEW WITH 
THE BARBERRY. 
Has the barberry really anything to do with the mildewin wheat? This question 
is one of great practical importance to the agriculturist, and through him to all 
classes of the community. It is by no means a novel one, and cannot be shelved 
as a new-fangled notion too crude to be worth investigation; for it is just a 
century ago, this present year, that the first recorded experiment bearing upon 
the question was performed, in the same county in which these lines are penned. 
Seventeen years ago the connection was proved to the satisfaction of Continental 
botanists, but many of us in this country and in America either denied it 
altogether or accepted it in a half-hearted sort of way. The magnitude of the 
interest at stake, as well as the great importance of the subject from a scientific 
point of view, demand that we should take the trouble to decide one way or the 
other. If the experiments upon which the assertion of this connection is based 
will not bear repeating, let us cast the vaunted theory to the winds and have done 
with it. But if, upon the other hand, these experiments prove the connection, 
let us accept it although it does uproot our prejudices and entails the acceptance 
of a great deal which, at present, we regard as too wonderful to be true, for Puc- 
cinia graminis is by no means the only case of the kind. 
It was in the hope of being able to arrive at a definite conclusion one way 
or the other, that the writer, in the summer of 1881, performed a series of experi- 
ments* by infecting a number of wheat plants with ripe spores of the barberry 
fungus, with this result, that while 76 per cent. of the infected plants took the 
disease, no less that 70 per cent. of similar wheat plants, which were kept as 
check plants, became spontaneously affected with mildew. The natural conclu- 
sion arrived at was, that 6 per cent was not conclusive evidence. It is obvious 
that mildew is a highly infectious disease, and the necessity for a less rough 
method of experiment is demanded if unequivocal results are to be obtained. 
In the spring of this year (1882) another series of experiments was instituted, 
in which not only was the barberry fungus sown upon wheat, under circumstances 
* Plowright, Grevillea, vol. x., p. 33—41.- 
