360 
ON CROSSES AND 
cum sempervirens by the scarlet arboreum. The latter, 
which were curious little plants, are probably all dead, in 
consequence of his injudicious perseverance in exposing them 
at an early age in the open ground. I vainly endeavoured 
to rescue the last survivor from his hard treatment. It is 
remarkable that the difference of constitution between the 
Rhododendrons and the American Azaleas seems to render 
the mules more impatient of wet than either of the parents, 
which is manifested by a sickly variegation of the leaf, ren- 
dering it often difficult to rear them, and indicating the 
want of a more sandy and drier soil. This may be the con- 
sequence of crossing a deciduous with an evergreen species. 
It is probably on account of that discrepancy that no seed 
has been yet obtained from any Rhododendro-Azalea, though 
the crosses of evergreen Rhododendra are sufficiently fertile, 
and I have raised seedlings from Azalea Pontica-viscosa v. 
alba, and Calendulacea-viscosa v. rubescens, though neither 
are disposed to seed freely. The intermixture of the white 
Rhododendron maximum, which is not an accidental variety, 
but a widely-spread and permanent kind on the mountains 
of Jersey in America, with Ponticum, has afforded a beautiful 
white cross, which reproduces itself in perfection by seed, 
and from that, or the American white itself, with Azalea 
Pontica or the yellow Sinensis, or the still more splendid 
orange varieties of calendulacea, we may expect to obtain 
various Rhododendrons with more decidedly yellow flowers, 
hardier constitution, and larger stature than R. Chrysan- 
thum. Seedlings from the white American Rhododendron, 
and also from a cross between Maximum and Ponticum, im- 
pregnated by me with pollen from Az. calendulacea v. chry- 
solectra, were in cultivation at Highclere, but they have 
been mislaid and perhaps lost. The fragrance of the Azaleas 
had been communicated to the Rhododendron, both by the 
Mitcham crosses and that of Mr. Chandler. The Indian 
Azaleas are probably capable of intermixing with the rest of 
the genus Rhododendron, and the beautiful lilac cross obtained 
by Mr. Smith abundantly between phoenicea and the white 
or ledifolia is very fertile, and has produced a great number 
of vigorous seedlings at Spoft’orth. Rhododendron Ponticum 
and Catawbiense have produced a cross which far excels the 
natural sorts in the size and complication of the umbels of 
flowers, and is amazingly florid, and the further cross Alta- 
clarse between that and the scarlet arboreum is of a colour 
