May 1, 1905 
THE AUSTRALIAN GARDENER. 
11 
cation of petals. But when the imducing 
causes’ of doubling are considered, there is 
ample opportunity for speculation. In a 
general manner, the causes assigned by 
physiologists, or the plans preposed by cu:- 
tivators, are reducible to three heads— 
namely, plethora, starvation, and sterility. 
As Dr. Masters stated many years ago, these 
three seem in consistent one with the other, 
bub are not so much soi as they appear at 
first sight to be. 
plethora theory have much in their favor ; 
for instance, the greater frequency of 
double flowers among cultivated plants 
than among wild ones. Dr. Seemann 
brought out the facts of the great pre- 
ponderance of double flowers in plants de- 
rived from the northern hemisphere, when 
contrasted with those from: the southeri. 
Cases have been. known of debility or star- 
vation having the effect of changing flowers 
to the double form ;but then it has ‘had a 
contrary effect also, as ai case hag been men- 
tioned of a double-flowered thorn produc- 
ing single blossoms from: this cause. Mr. 
Darwin makes menition' of a state of things 
which brings about sterility or imperfect 
formation of the flower, leading to a conse- 
quent increase of the [petialine element, 
either in the form of an increased number 
- of bracts, petals, &c., or in the substitution 
of petals for stamens and pistils. 
It is said that the way in which double 
stocks are produced in Erfurt is by giving 
the plants a minimum, supply of water. 
This much appears to be certain, that when 
once the disposition to form double flowers 
is established from any cause, that ten- 
dency becomes hereditary ; there are races 
of stocks in which out of hundreds of plants 
scarcely one double flowered form is met 
with; this is particularly so in the case 
with the Giant Brompton, and especially 
‘so in the case of the White Giant; on the 
other hand, where the tendency is set up, 
single flowers become the exception.—R. 
Dean, in “Horticultural Trade Journal,” 
Eng. 
a 
CAN SPORTING IN PLANTS BE 
INDUCED? 
The sporting of plants, as we term: the 
vegetative variations which occur during 
the life of the individual, is only a special 
form of variation. Variation we know is 
the natural tendency of plants and. ani- 
mals. 
variation is frequently predetermined by 
external circumstances—environment—or 
by inherent tendencies of the individual 
or species. 
In fact, fixity of type, either in nature 
or under cultivation, is a very difficult 
‘thing to attain, as all seedsmen and plants- 
men well know. The fixity which’ appears 
tio exist in nature and which is responsyble 
for the existence of so-called species, is the 
result of certain limiting forces working 
in conjunction, through countless genera- 
tions. Break up this dead-lock, and the 
species almost invariably throws off varie- 
The advocates of the © 
The direction and extent of such 
tics——a convenient term for indicating a 
departure from the parent type. 
Brom what has been said it will be evi- 
devt tnat I consider a sport simply a 
mevked variety or variation, which may 
appear as a distinct individual, or as a 
part. of an individual during its period of 
existence, in which case, for purposes of 
distinction, we are pleased to call the lat- 
ter a bud sport or variety. 
Sporting, then, may be encouraged by 
extreme conditions. Hither extreme feed- 
ing or extreme poverty may induce plants 
to sport. Severe changes in climate or 
soil conditions may result in decided chan- 
ges in stature, habits of growth and fruit- 
fulmess, which are as marked attributes of 
a sport as are changes in the colour of 
foliage or fruit. 
Burpee dwarf lima bean is al good ex- 
ample of a sport where the habit of the 
plant was markedly changed. The white 
and fancy sports of the Lawson carnation 
are good illustrations of changes in colour. 
Just here I wish to note that in a bed 
of Mrs. Lawson and upon a plant: with 
otherwise normal flowers, one shoot pro- 
ducea a blossom, one-half of which was 
pure white, while the other half was of 
the normal pink of the Lawson. These 
sports in the Lawson are exceedingly in- 
teresting, for they clearly indicate that 
the Lawson is composed of two parts, pink 
and white, in which the pink is the pre- 
dominant. Under! favourable conditions, 
however, the white asserts itself, and we 
have the sports above spoken of. This 
frequent breaking out of a recessive cha- 
racter is all the more interesting in the 
case of the Lawson carnation on account 
of the fact that neither of its immediate 
parents were white, the Lawson, being the 
result of a cross of Daybreak, pink, with 
Van Leeuwin, cerive. The facilities now 
at hand do not allow me to analyze the 
composition of either Daybreak or Van 
Leeuwin, but I suspect from the behavi- 
our of Lawson sports thati one of these 
parents, and perhaps both of them, have a 
strong white strain of blood: in them’ 
From what has been said it is evident 
that cross-pollination is| believed to be one 
of the most important means through 
which the sporting or variation of plants 
can be induced. The wonderful results 
obtained by Burbank in his work with, 
fruits has ‘been based almost entirely upon 
the practice of cross-pollination. In con- 
nection with this work, there seem’ to be 
two pretty well established theories. They 
may be stated somewhat as follows:— 
When working with species the more vio- 
lent the cross that can be secured the 
more variable will be the hybrids in the 
second generation, and the more’ likeli- 
hood there is of securing distinct forms of 
monstrosities. Second, thati when working 
with plants which are themselves of cross- 
bred or hybrid origin the peculiar attri- 
butes of the particular plants used for 
breeding purposes cannot be counted upon 
to appear in the mongrel offsprings, ex- 
cept in so far as these characters form) im- 
portant dominant or recessive characters 
in the breeding of the parent plants. 
The marvellous results achieved by some 
of cur moderate plant breeders seem to lie 
in their wonderful skill as manipulators of 
plants. Crosses have been! successfully 
made by these men, and fertile seeds ob- 
tained from. plants which have been, con- 
sidered incompatible and so entirely dis 
tinct, that it was considered heresy to 
seriously consider the question: of making 
such ai cross. I am. free to confess that 
with ninety-nine persons out of every hun- 
dred ‘engaging in such work TI believe the 
results would be “nil.’ The success of the 
one proves his superior skill and ability 
to discern the conditions essential for suc- 
cess. 
The factors, then, which may be con- 
sidered as contributing to the sporting of 
plants are: Extreme conditions in the cn- 
vironment, such as marked changes in 
latitude, altitude, soil conditions, as from 
alluvial to desert, increased food supply, 
the results of an excessive use of plant 
foods or of cultivation,-and. violent or con- 
tinuous cross-breeding.—L. ©. Corbett be- 
fore the American Institute, New York. 
SCARLET SALVIAS. 
If you have any old plants place in a 
good, light position in the greenhouse— 
that is to say, a structure whose minimum 
temperature is about 45 degs. Give suf- 
ficient water to keep the soil slightly 
moist, but no more; indeed, the object 
is to maintain the plants in a; quiet state 
till the spring, when. young: shoots will be 
pushed out freely. These shoots will 
strike without difficulty if taken, off at 
a length of about 3 inches, dibbled into 
pots of sandy soil, and placed in a close 
propagating-case in the warmest part of 
the greenhouse. Of course, these cuttings 
must be shaded from the sun till rooted. 
When. potted off pinch out the growing 
points in order to encourage a bushy 
habit, and, directly the roots take hold of 
the new soil, give plenty of air. Poti on as 
may be necessary, and grow in the open. 
air during the summer, bringing them into 
the greenhouse in! the autumn, where they 
will come into flower. One thing to be 
particularly careful about during the early 
stages of this Salvia under glass is to see 
that the foliage does not get affected by 
red-spider, as it soon causes ai good deal 
of damage. Too dry an atmosphere is es- 
pecially favourable to the development of 
this pest. 
VIOLET CULTURE. 
I have seen various notes as to growing 
and watering violets im gardening and. 
other journals. My method of culture for 
both single and double varieties is as fol- 
lows: I take the young rooted runners 
that have not: flowered from the old plants 
that have done blooming, dibble them into 
qaede “ut G 480M 10 gee Sutoey sepsoq v 
each waiy, water them in well, and continue 
the watering throughout the summer, 
Never let them! want for water at any time 
