96 JOURNAL OF HORTICULTURE AND COTTAGE GARDENER. t February 2 , im. 
30 feet long and 14 wide, with front and back stage, and shelves 
along each end. The house is divided into two compartments. 
In one there is one Muscat and two Black Hamburgh Vines. 
This compartment I keep at a temperature of from 50° to 58° 
according to the weather. The front stage is occupied with a 
selection of Zonal Pelargoniums, grown by the sides of the garden 
walks expressly for winter. The shelf at one end has Roses in 
pots, and at the other end Perpetual Carnations grown similarly 
to the Zonals, which in the light position and temperature named 
have flowered freely all the winter, and will continue to do so for 
some time. The back stage is occupied with a standard Rose or 
two, Heliotropes, Callas, and the plants usually met with in such 
structures. The Vines start in January, and the Hamburghs are 
ripe at the end of June. The border is inside each compartment, 
and the Vines are allowed each year a moderate crop of about 
18 tbs., the Muscats rather more. 
In the other compartment there are three Black Hamburgh 
Vines, which are retarded to succeed the others, and by liberal 
applications of weak liquid manure finish similar crops. The 
front stage in this house is occupied by Primulas followed by 
Cinerarias, and the shelves contain Cyclamens, Hyacinths, and 
herbaceous Calceolarias. This compartment is kept at a tempera¬ 
ture of from 42° to 52° according to the weather. I find that the 
temperatures named do not unduly excite the Vines, which 
ripen their crops in September and usually last till Christmas. I 
have had Camellias in both houses since November. By training 
the laterals rather thinly and allowing as much growth past the 
bunches as possible, I find the Vines are greatly benefited, and it 
also enables me to grow Tuberous Begonias, Fuchsias, and Ferns 
in summer. But we have our best display during the winter, 
when they are most appreciated. We are rarely without a Rose 
or Carnation for a button-hole, and plenty of Pelargonium trusses. 
In addition to the plants named, I find Bouvardia Vreelandi, 
Cytisuses, and double Primulas particularly useful for cutting in 
winter. 
If you think a few notes on Zonals or Carnations would be 
useful, I will seud them with varieties I find succeed best for 
winter.— W. Wallace, Yardley. 
[Such notes as you can send will be very acceptable.—E d.] 
SOME SEXUAL PECULIARITIES OF PRIMULA 
SINENSIS. 
Anyone who has experimented with crossing different forms 
of the Chinese Primula cannot fail to have been struck with 
certain peculiarities which invariably follow particular modes of 
fertilisation. I have often seen it stated that among Primroses 
in general the loug-styled and short-styled forms appear in 
nearly equal numbers. Growers of Chinese Primroses must have 
been struck with the fact that, in this case at least, the general 
rule does not hold true. Sometimes nearly a whole batch is 
short-styled, at other times as nearly wholly long-styled. I have 
observed that seed from a certain seedsman who saves his own 
seed belongs to one form, while that from another belongs to 
another form. A year or two ago, before saving seed, I imagined 
that such was one of the peculiarities of the particular strain, 
though these are not quite so numerous as those not in the secret 
might suppose. 
A year or two ago the seed from a respectable firm produced 
plants among which there was not one of the short-styled form. 
Determined to raise seed scientifically—that is naturally—I pro¬ 
cured a few flowers of the short-styled form from a neighbour, 
and with the pollen from these short-styled flowers ours were 
fertilised. Those operated on set a good crop of seed, which in 
due time ripened, was sown, and produced plants which, when 
they flowered, produced flowers mostly short-styled. Referring 
to notes made at the time I find that 67 per cent, were short- 
styled, the remaining 33 being of the opposite form. 
Again, the long-styled forms were fertilised with pollen from 
the short-styled, and when the resulting plants flowered produced 
a still greater per-centage of short-styled flowers. Thinking this 
result rather curious I fertilised some plants of the long-styled 
form with pollen from long-styled flowers, and some short-styled 
flowers were fertilised with the same. The resulting plants were 
similar to their parents ; the seed from the long-styled forms 
producing, almost without exception, long-styled flowers, and the 
short-styled flowers giving birth to short-styled flowers. At this 
point the experiments were stopped. 
Seed from self-fertilised flowers—and this is the too general 
way practised by ordinary growers—is not only sparingly pro¬ 
duced, but does not result in such healthy offspring. Indeed the 
fact, as pointed out by Darwin and others, is pretty fairly estab¬ 
lished, that cross-breeding tends to produce vigorous offspring. 
This result, cross-breeding, has been secured for Primroses natu¬ 
rally, for in nature we do not suppose that a single flower is 
self-fertilised, or even fertilised with pollen from the same form. 
At all events, pollen from short-styled and long-stamened flowers 
is prepotent when applied to the stigmas of long-styled flowers. 
There seems to be a rule that the length of the tubes which 
pollen grains produce depend, to a great extent, on the length of 
the stamens from which the pollen was taken. Thus pollen from 
short-stamened Primroses when applied to forms similar to that 
from which it was taken— i.e., long-styled — is mostly useless 
because of its inability to produce tubes long enough to reach 
down the long styles to the ovaries. That a few grains occasion¬ 
ally do so we are perfectly aware, otherwise fertilising Primroses 
by pulling the tube over the stigmas, and so dusting them with 
their own pollen, would always fail; whereas it, as too many are 
aware, occasionally partially, seldom fully, fertilises the ovules ; 
but the resulting offspring are usually weak. 
Why weak pollen applied to long-styled forms of Primroses 
should generally fail does not seem as wonderful as the opposite 
fact, that stronger pollen from long stamens (thrum eyes) applied 
to short-styled pistils—that is, those of their own form, should 
also fail. In this case it seems that the pollen tubes either go 
past the ovules altogether or rupture them, and any that success¬ 
fully fulfil their office do so by reason of their weakness; this 
also resulting in weak progeny. 
Now Nature never goes wrong in this matter. She provides 
that the flowers that have loDg styles shall have short stamens, 
and those with short styles shall have long stamens. A wander¬ 
ing bee alighting on a long-stamened Primrose, in thrusting his 
proboscis down the tube of the flower in search of the honey-filled 
nectary, smears, all unintentionally, his head with pollen among 
the stamens which cluster, and, as the florists maintain, orna¬ 
ment the mouth. Possibly the next flower he visits has the pistil 
protruding from the tube, and as he reaches down to find the 
honey he dusts the stigma with pollen and secures its fertilisation. 
Not only so, he this time smears his proboscis among the stamens 
which lie near the bottom of the tube, and arms himself with 
pollen just suited to fertilise the short pistils which any interested 
reader will find stand inside the tube at the very same height as 
the stamens in the long-styled forms. 
A wonderful arrangement, for should any plant be produced 
the stamens or pistil of which had not corresponding stamens and 
pistils in other flowers, it would either fail to leave offspring at all, 
or leave it of such a weakly nature because of the too close inter¬ 
breeding that, in the struggle for existence, its race would go to 
the wall. Were it to appear among men’s productions it might 
be kept living by artificial modes of cultivation, but even then its 
race would be comparatively short. It would then be fertilised, 
if fertilised at all, unnaturally, for crossing is not less natural than 
necessary. In-and-in breeding never fails to weaken, though that 
result may not be apparent just at first. Hence Nature, whether 
she provides dimorphous plants as in the case of Primroses, plants 
bearing male and female flowers as in the case of the Melon, or 
on different plants as in the case of the Aucuba, or merely makes 
the carried pollen prepotent as among Peas and Cabbages, always 
aims at cross-breediDg in order to avoid the weakening influence 
of self-fertilisation. 
These remarks may serve to arouse our younger readers to 
inquire into the subject of seed-raising. Many as are the hands 
engaged in raising new and if possible improved forms of flowers, 
fruits, and vegetables, there are not enough, and if one out of every 
ten gardeners were to try and improve something, in ten years 
hence we would make an advance not dreamed of. Much effort 
is thrown away because much is wrongly directed. Even in the 
matter of raising Primula seed the vast majority, instead of help¬ 
ing Nature, fight against her. Not many raise their own seed— 
they have tried and too often in vain. Let them try again on the 
lines here laid down, and if they provide conditions otherwise 
suitable we will guarantee the same success among their Chinese 
Primroses as Nature secures for them without their own interven¬ 
tion among their hardy Primroses outside.— Single-handed. 
SILKWORMS AND SILKWORM-REARING.—6. 
The eggs or grain of the silkworm (Bombyx Mori) pass through 
various changes of colour between the periods of deposition and 
of hatching. When laid they are bright yellow ; this alters to 
brown in about a week. Should they remain yellow or become 
paler there is sufficient proof of their unproductiveness. Brown 
gradually becomes a slaty grey, this hue remaining through the 
autumn and winter. The first intimation that the process of 
hatching has commenced in the spring is given by another 
