16 
published by Sir Joseph Banks in 1805. In- this tract ‘will be 
found very accurate and highly magnified figures of this fungus in 
various stages of growth, as it appears on the straw of wheat, 
delineated by Bauer, who was the first botanical draughtsman of 
that day. 
Mildew is much more prevalent some seasons than others. 
The alarming deficiency which it caused in the yield of wheat, in 
the harvest of 1804, was the cause of Sir Joseph Banks taking 
up the subject, and publishing the year following the tract just 
alluded to. The spores of the fungus, by which mildew is caused, 
are present all years and generally diffused ; but to what extent 
they are developed, and whether so far as to be productive of any 
serious mischief, probably depends upon seasonal influences (like 
the potato disease, also due to the growth and spread of a small 
species of fungus), combined with peculiar conditions of soil, and 
the state of the wheat plant itself at the particular time when the 
germination of the fungus takes place. Both Mr. Stephens and 
Mr. Davis speak of its coming on after rain ; and that it abounds 
most in wet summers, to the especial prejudice of corn that has 
been much laid by wind and rain together, is what I suppose all 
agriculturists would allow. 
At the conclusion of Mr. Davis’s remarks, reference will be 
found to what he terms “a very singular but well ascertained 
fact, viz., that a berberry bush in a wheat field will produce an 
effect very similar to the blight, without any appearance of fungus 
on the straw.” The latter part of this statement I doubt being 
correct ; but the circumstance of the connection between mildew 
and a berberry bush is a very curious one, and all the more so 
from this apparent anomaly having been only within the last few 
years cleared up ; if, indeed, it be yet quite cleared up. It has 
been over and over again asserted that such a connection does 
exist, however it may be explained, and over and over again as 
stoutly denied. The supposed connection was grounded upon no 
end of cases brought forward, in which the mildew upon the 
