Proceedings 49 
moreover, found possible to control or even stop the disease 
by throwing finely-divided sulphur over the leaves and young 
grapes, a practice followed to this day. It must be noted, how- 
ever, that the fungus has never left Europe since its first visit- 
ation in 1845,and at the present time still causes a great annual 
loss, being certain to appear sooner or later wherever grapes are 
grown, and then can be kept in check only at the cost of repeat- 
ed sulphurings which entail much labour. In fact, Europe is 
taxed annually to the extent of hundreds of thousands of pounds 
for having neglected to stamp out the vine-mildew on its first 
appearance in Europe. 
A curious point in connection with this vine-mildew is that 
for 47 years after its first appearance in Europe its exact iden- 
tity was not discovered, since during all these years the mildew 
either did not complete its full life-history or no one was able 
to observe it. In 1892, however, the further stages of its devel- 
opment were found in France, and its full life-history thus 
became known; it was then found that the so-called ‘Ozdium 
Tuckeri’ was identical with a mildew called Uncinula necator, 
long known as attacking both wild and cultivated species of 
Vitis in North America. It is probable, therefore, that the mil- 
dew was introduced into Europe about 1845 on diseased vines 
imported from the United States. 
Another instance of the introduction into Europe of a des- 
tructive fungus attacking fruit is that of the American Goose- 
berry-mildew (Spherotheca mors-uvae). At the present time 
this mildew is invading Europe in exactly the same manner as 
the Vine-mildew did in the Forties. The American Gooseberry- 
mildew was imported about the year 1900 into Ireland, Russia 
and Denmark on diseased gooseberry-bushes obtained from the 
United States. In 1900 the mildew was discovered in one or 
two spots in Ireland—its first recorded appearance in Europe; 
nothing was done to check its spread, and it is now widespread 
over practically the whole of Ireland. Soon after 1900 it broke 
out on the Continent—in Russia, Denmark, Sweden, Norway, 
Finland and Germany. In 1906 it was first found in England; 
outbreaks have now occurred in most of the fruit-growing cen- 
tres in this country. This fungus, besides covering the young 
