ingle-flowered pinks, in the seedling state.
According to this gentleman, those seedlings which produce three
cotyledons in a whorl in place of two, form double flowers. In the case
of _Primula sinensis_ the same results occurred. Some had three leaves
in a ring, others two; most had the leaves standing one over the other
as usual. These were divided into three sets, and when they flowered,
the first lot were all double, the second semi-double, the third single.
But these statements have not been confirmed by other observers; and the
writer can safely assert that seedling pinks occasionally produce three
cotyledons, and subsequently single flowers. He has never observed a
double flower under these circumstances, though it is true his
experience in this matter has been but small.

A writer in Otto's 'Gartenzeitung,' considers that double flowers are a
consequence of dryness of soil and atmosphere, and not of a luxurious
soil, rich in nutritious matter, having arrived at this conclusion from
an observation of the following circumstances:

"Fifty years ago we saw _Kerria japonica_ in a hothouse with single
flowers. Twenty years later we met with it in several gardens, in the
open air, but always with double flowers. At this time we were assured
that single-flowered plants were no more to be found in the whole of
Europe, and botanists forming herbaria offered considerable sums for a
branch of _K. japonica_ with single flowers. We were requested to take
the plant in hand for the purpose of inducing it to produce single
flowers. We were advised to plant it out in a rich soil, which was done,
but, by chance, the situation was sloping, consequently it did not
retain moisture, and all the flowers produced for several years in
succession were double. Shortly after, the captain of an English ship
again brought plants bearing normal flowers from Japan, which were soon
spread over the continent, and of which we received one plant. After
three years all the young plants raised from cuttings were
double-flowered.

"In the year 1820 we several times visited a garden in the neighbourhood
of Vienna, well known on account of its plant culture. The gardener
there possessed an immense plant of _Camellia japonica_ with single
flowers, and some small plants raised from this by cuttings, but no
other variety of camellia. He fertilised the flowers with their own
pollen, harvested seeds, which he sowed, and the plants raised from them
were pl