39 
no other variety near to it from which pollen could be 
carried by seed. Even in orchards, if a large number of 
self-sterile varieties are grown close together, the yield of 
fruit may not be found to be satisfactory. In both cases 
it has proved very efficacious to plant near such trees a 
Siberian or other Crab Apple, which produces a’ large 
amount of effective pollen which can be carried by insects 
from tree to tree. 
After fertilisation, when the young plant is beginning 
to be formed in the seed, the seed vessel too begins to 
swell, and it is from observing the latter that we can 
gather that pollination has been successful. Of course 
the continued growth of the seed-vessel, as well as the 
development of the embryonic plant and the storage in the 
seed of enough food material for its subsequent germina- 
tion, necessitates considerable activity on the part of the 
vegetative organs particularly of the leaves. It is for this 
reason advisable in the case of Peas, Scarlet Runners and 
French Beans, when they begin to set their pods, to 
encourage their further growth by the use of suitable 
stimulants such as liquid manure. 
It is obvious that as the formation of seeds and fruits 
require increased supplies of food material, herbaceous 
plants that are heavily fruiting will have less food where- 
with to develop new flower buds, and graduallv the plant 
will cease to produce flowers. If, therefore, we are culti- 
vating plants for the sake of their flowers it cannot be 
too strongly recommended to pluck off all flowers as soon 
as they are dead, so that they should not begin to sct 
their seeds. In the case of Sweet Peas, where the seeds 
take up a large amount of food material, this is par- 
ticularly important, but it 1s a good rule to follow in all 
cases. The fact that a large supply of food material to 
fruits may exhaust that available for the production of 
flower buds will explain reduction in the number of 
flowers on fruit trees, if an abnormally heavy 
crop of fruit was produced in the previous season. 
It is not, however, only the formation of flowers 
which will be interfered with. Under special cir- 
cumstances the vegetative organs, too, may suffer. 
For this reason it is recommended that young 
fruit trees, which have been recently transplanted, should 
not be allowed to ripen many of their fruits during the 
first season after transplantation, as this may interfere 
