or black, according to the variety,--nearly thirty
thousand are contained in an ounce, and their vitality is retained five
years.

_Soil._--Lettuce succeeds best in rich and comparatively moist soil; and
is also best developed, and most crisp and tender, if grown in cool,
moist weather. A poor soil, and a hot, dry exposure, may produce a
small, tolerable lettuce early in spring, or late in autumn; but, if
sown in such situations during the summer months, it will soon run to
seed, and prove nearly, if not entirely, worthless for the table. The
richer the soil may be, and the higher its state of cultivation, the
larger and finer will be the heads produced; and the more rapidly the
plants are grown, the more tender and brittle will be their quality.

_Propagation._--It is always grown from seeds, which are small and
light; half an ounce being sufficient to sow a nursery-bed of nearly a
hundred square feet. It is necessary that the ground should be well
pulverized and made smooth before it is sown, and the seeds should not
be covered more than a fourth of an inch deep.

_Cultivation._--Some recommend sowing where the plants are to remain, in
drills from ten to fifteen inches apart, and thinning the plants to
nearly the same distance in the lines; adapting the spaces between the
drills, as well as between the plants in the drills, to the habit and
size of the variety in cultivation. Others recommend sowing in a small
nursery-bed, and transplanting. The process of transplanting
unquestionably lessens the liability of the plants to run to seed, and
produces the largest and finest heads. The first sowing in the open
ground may be made as soon in March or April as the frost leaves the
ground; and, if a continued supply is desired, a sowing should
afterwards be made, at intervals of about four weeks, until September.
"During spring, the young crops must be protected from frost, and in
summer from drought by copious manure-waterings and frequent stirring of
the ground between the plants. In the growing season, every stimulant
should be applied; for much of the excellence of the crop depends on the
quickness of its growth."

_Forcing._--Lettuce is now served at table the year round; not, of
course, of equal excellence at all seasons. Sowings are consequently
required for each month: those intended for the spring supply being made
from December to February; about twelve weeks being required for its
full development, when reared