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menced, and late in the fall, when it has almost ceased, the sap is con¬ 
centrated in the roots, and if the sod is then turned over, many of the 
roots of grasses and other plants retain their vitality, and shoots from 
the curve upwards and make their way through the sod to the light; 
just as the plumule of a seed would do, if a seed were placed in the soil 
wrong side upwards. As the luxuriant growth of a plant in spring de¬ 
pends in a great measure upon the quantity of organizable matter it can 
command, means may be adopted to increase the quantity and with 
various objects in view, such, for instance, as to increase the size of bulbs 
the produce of roots, flowers, or seeds, or to hasten the period of the 
blossoming and fruiting: of trees. 
Andrew Knight adopted a novel plan of cultivating the onion. In the 
long and warm summers of the south of Europe, the onion attains a 
much larger size in a single season than in the colder climate of England. 
But by the following mode of culture which Mr. Knight had long prac¬ 
tised, he found two summers in England produced nearly the effect of 
one in Spain or Portugal. “Seeds of the Spanish or Portugal onion 
were sown at the usual period of the spring, very thickly and in poor 
soil, generally under the shade of a fruit tree ; and, in such situations, 
the bulbs are rarely found much to exceed the size of a large pea. These 
are then taken from the ground and preserved till the succeeding spring, 
when they are planted at equal distances from each other, and they afford 
plants which differ from those raised immediately from the seed only in 
possessing much greater strength and vigor, owing to the quantity of 
previously generated sap being much greater in the bulb than in the 
seed.” 
Andrew Knight, in raising very early varieties of potatoes in the open 
ground, was in the habit of selecting, in the fall, the largest tubers, and 
those nearly of an uniform size, for planting in the spring ; and he found 
that these always afforded very strong plants, which readily recovered 
when injured by frosts, owing to the large store of organizable matter 
they contained. It would seem, at first sight, most advantageous in all 
cases to plant large tubers rather than small ones, or than sets. The 
greater the amount of organizable matter the tuber can supply to the 
young plant, the more vigorous should be its growth, the greater the 
breadth of its foliage ; and in proportion to the extent of its foliage, so 
