172 THE FLORAL WORLD AND GARDEN GUIDE. 
visit flowers do harm to the private grower by destroying the purity 
of his varieties, they do good to the other by preserving the purity 
of his varieties. When a piece of, say, ten to twenty acres of 
broccoli is grown for seed, the bees are busy upon it all day long 
from first to last. They do not carry the pollen to impregnate other 
varieties and spoil them; they distribute the pollen where it is 
wanted, because they have a great pasture, and therefore need not 
quit it for food, and therefore do not carry the pollen away. We do 
not, of course, account for the actions of every individual bee, nor 
affirm that crosses do not occur where seeds are grown in large 
quantities; but it is a matter of fact that, in a broad and practical 
view of the subject, the case is as we put it. Those who grow 
seed for the market have many advantages over those who grow for 
their own use, and, in respect of certain kinds, the purity of the 
stock depends in great measure on the quantity grown in any one 
particular spot. 
In saving seeds in gardens, the greatest care should be taken to 
maintain the purity of good stocks. One mode of procedure, 
having this end in view, is to allow only one amongst many closely- 
related varieties to be in bloom at the same time, especially of things 
like brassicas that freely cross and intermix. Another important 
matter is to secure the best sample possible by boldly thinning out 
the flower-stems, and reducing the ultimate bulk of seed; for 
almost every plant produces more fruit than it can mature perfectly, 
and the more desirable it is that the quality should be good, the 
more necessary it is to keep a watch that there is no excess im 
quantity. Asa rule, the strongest and most fruitful plants of every 
kind are the produce of the heaviest seeds. The specific gravity of 
a seed is to a great extent a measure of its relative vigour, and a 
high specific gravity of the seed is as truly worth aiming at, by 
careful selection and judicious cultivation, as any other quality that 
can be named. Of course, when seeds of any kind are grown in 
great breadths, thinning the crop is out of the question; but some- 
thing may nevertheless be done to prevent deterioration, as for 
example, the heaviest seeds may be separated for the seed crop, and 
the rest may go for green crops and consumption. 8S. H 
HIBBERD’S TRIANGULAR EDGING TILE, 
===y HIS tile was designed for a special purpose; but, having 
1 been seen by many, has acquired a certain subdued sort 
of fame, and is occasionally the subject of inquiry. It 
is in no sense ornamental, but it is peculiarly substantial, 
affording great support to the border, and, being hollow, 
it does not retain moisture, and, therefore, it is not injured by frost. 
Those that have been in use six years at Stoke Newington have not 
suffered so much as a chip, while other kinds of tiles in the same 
garden have literally rotted away through the action of frost upon 
