254 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 
by to attack it. This may be proved by growing certain varieties 
notoriously prone to mildew under glass and treating them to an 
application of sulphur fumes from Campbell's or any other vaporizer. 
They are for the time being encased in a coating of sulphur that 
defies the mildew spores, and it is only when new growths appear 
that attacks succeed if the vaporizing is not persisted in. 
Now, we cannot encase Roses outdoors in like manner, however 
carefully we spray them, so that to have Roses free of mildew we must 
raise Roses with mildew-resisting foliage. 
I readily confess that the subject opens out possibilities that are 
far too vast for me to attempt to describe in the limits of a paper, 
but I will endeavour to give a few ideas that may form the basis for 
some hybridists who have the opportunity to experiment. 
I have noticed, as no doubt most observers have done, that mildew 
is very rife among some of the old tribes of Roses such as Rosagallica, 
and I think we can very justly blame them for handing down to 
the so-called Hybrid Perpetuals this tendency to mildew, which has 
been largely responsible for their banishment from modern gardens. 
Take old * General Jacqueminot ' for instance, or ' Abel Carriere/ or 
' Mrs. Sharman Crawford/ what terrors they are for mildew ! Did 
they inherit it from the ' Gallicas ' or ' Damask Perpetual ' ? 
To show that Roses have the power to perpetuate the plague among 
their descendants, I may point out one example. 
We all know that the ubiquitous ' Dorothy Perkins ' is a Rose 
frequently blighted by mildew, and we know it has not inherited 
it from R. Wichuraiana, its seed parent, but from 'Mrs. Sharman 
Crawford/ its pollen parent. I do not claim that this is an absolute 
test, because probably instances could be cited of the reverse action ; 
but I will give an illustration on the other side. 
One of the grandest Rambler Roses of modern times is 'American 
Pillar/ a Rose with glorious foliage and splendid trusses of blossom. 
This was raised by Dr. Van Fleet, of the Department of Agriculture, 
Washington, from R. Wichuraiana X R. setigera. Here we have an 
instance of a thick leathery leaf, such as R. setigera produces, being 
blended with the tiny foliage of R. Wichuraiana, and yielding the 
grand foliage of this fine variety. R. setigera was also one of the 
parents of ' Reine Olga de Wurtemberg/ which is also renowned for 
its beautiful mildew-resisting foliage. 
As is generally known, R. Wichuraiana has been largely employed 
by Rose-hybridists as the seed parent of many of our best Ramblers, 
and when it has been crossed with the glossy-leaved Tea Rose it has 
produced mildew-proof foliage. Such examples are found in ' Jersey 
Beauty/ ' Leontine Gervais/ ' Alberic Barbier/ ' Francois Juranville/ 
' Dr. Van Fleet/ ' Miss Helyett/ ' Edmond Proust/ ' Gardenia/ and 
many others. 
It seems therefore, if we would continue this type, we must use the 
glistening-foliaged Tea and China Rose as pollen parents. Strangely, 
by crossing R. Wichuraiana with large-flowered Hybrid Perpetual Roses 
