JOURNAL OF HORTICULTURE AND COTTAGE GARDENER. 
March 1, 1883. ] 
169 
1st 
Tn 
Roval Society at 4.30 P.M. 
2nd 
P 
Linnfcan Society at 8 P.M. 
3rd 
s 
4th 
SUN 
4th Sunday in Lent. 
Sth 
M 
6th 
TU 
7th 
W 
Society of Arts at 8 P.M. 
CROSS-BREEDING PRIMULAS AND 
AURICULAS. 
ARWIN ’ S dictum that “Nature abhors 
^ self-fertilisation ” is so generally 
ac¬ 
cepted that it may almost be regarded 
as a truism, although unbelievers lay 
much stress on the few exceptions, which, 
however, only prove the rule. Applied to 
plants, cross-fertilisation commonly means 
the fertilisation of the ovules through the 
$>)'• stigmas of one plant by means of pollen from 
^ another individual of the same species. There 
are, however, in some cases individual species, 
and in others whole orders, to which the general rule 
does not fully apply, and prominent among the latter 
is the Primulacege. 
Raisers of Auriculas have ignored this. The pollen 
from one florists’ variety is taken to fertilise the stigma 
of another variety, and the result is called a cross. 
In the scientific—that is to say natural—sense of the 
term it is not a cross, and the actual result from one 
point of view is even worse than self-fertilisation would 
be in ordinary cases. For instance, Melons, Vegetable 
Marrow, or Cucumbers fertilised with blooms from the 
same plant, which in their case is as near self-fertilisa¬ 
tion as can be, do not show any degeneracy in the 
offspring ; at least it is not marked. But in the case 
of Primulas the fertilisation of thrum-eyed flowers with 
pollen taken from thrum-eyed flowers of the same 
species, no matter how distinct the varieties may be, 
is always attended with partial failure as well marked, 
or even more so, than in the case of inveterate haters 
of self-fertilisation when self-fertilised. 
When all the ovules of a seedpod become perfect 
seeds the amount of seed is said to be normal, when 
below that it is abnormal. Now in the case of plants 
which “abhor self-fertilisation” the number of seeds 
produced in self-fertilised flowers are always abnormal 
more or less, varying from a slight deficiency to nothing 
at all; and this* is accompanied by lessened vitality, 
which generally diminishes from generation to gene¬ 
ration if the evil practice is continued. This is the 
cause of the recognised evil of what is called “ in-and- 
in ” breeding among domestic animals. The affinity 
of species is often tested in this way : When species 
are crossed, and the produce is normal or nearly so, 
species are considered to be nearly related; when very 
few or no seeds, and these of low germinating power, 
are produced, they are considered not so nearly related, 
although there are decided exceptions to this as to 
every other rule. In this instance varieties and species 
differ, for the more distant the variety (it may even be 
a sub-variety, or variety of a distinct race, such a& 
Brussels Sprouts and Scotch Kale) the likelier we are 
to have a full complement of seed, that seed of the 
plumpest type, and the progeny of the most vigorous- 
nature, surpassing in most cases the vigour of either 
parent. 
Primulas of all kinds, P, Auricula and P. sinensis 
in particular, when crossed artificially—that is, on 
florists’ principles—show by the very great diminution 
in the quality of the seed, its low germinating power,, 
and in the want of vigour in the progeny—all the evils 
of self-fertilisation. Those who have bought seeds at 
half a crown a packet, and found comparatively few 
seeds for their money, that even these germinated 
badly, and that such seedlings as did appear were very 
weakly. But the real fact is that seed is only obtained 
with great difficulty, in small quantity, and of by no 
means the best quality, when raised from Show or 
Alpine varieties when hi ature’s principles are thwarted 
in its raising. 
But florists will point to their very highly refined 
flowers, and, while admitting that a little more vigour 
in the plants might be desirable, will confidently ask if 
the results attained do not justify their mode of crossing. 
We admit they have produced flowers of exquisite 
beauty, and are deeply indebted to them for so doing, 
for they have produced what we may call strains of 
great merit, whereby we, taking Nature as our guide- 
and florists’ flowers for a beginning, may speedily pro¬ 
duce a race of robust hardy plants which will reproduce 
all the beauty of colouring, greater numbers of flowers,, 
and much of the refinement of florists' flowers, and, 
after all, this recognised refinement is itself regulated 
by an artificial standard. It is not intended that 
florists should learn from this, for possibly they know 
better, but a hint may serve even their purpose. 
Whether by adopting Nature’s plan equal results can 
from a florist’s point of view be obtained we will not 
venture to say. Greater results might be obtained ; 
certainly greater vigour in the plants would be secured ; 
and if the per-centage of flowers produced possessing 
the properties necessary be less, the much greater quan¬ 
tity of seed produced may make up for this, and it is 
not too much to suppose more. 
Perhaps a word on fertilisation may be acceptable in 
this place to those who may not be familiar with the 
subject. Nature provides for cross-fertilisation in a 
variety of ways. A very common one is that the 
stamens and stigmas in any flowers are not in con¬ 
dition at the same time. In some cases the pollen 
cases have burst, and the pollen been distributed by ; 
the wind or by insects, before the stigma becomes re- i 
ceptive; in other cases the stigma has been fertilised 
before the pollen has become ready. In a large number 
of instances most wonderful mechanical contrivances 
exist to prevent self-fertilisation. Darwin in his work 
on “ The Fertilisation of Orchids” has shown what a 
variety of amazing arrangements exist in even such 
a small number of plants as British Orchids to prevent 
self-fertilisation. Even when the stigma is receptive, 
when the pollen is ripe, and when no special contri¬ 
vances exist to prevent self-fertilisation, in a great 
number of cases foreign pollen—that is, pollen from 
another flower or another plant, is prepotent. 
Hybridisers wishing to cross a large species with a 
NO, UOr-VOL; VL» ISIBD gfiBIBS, 
No, 1706.—VOL. LXIX., Old &EBIE*. 
