The two boxes were set together across
the side bench of a greenhouse with the outer edge against a board wall
some 2-1/2 feet high, so that the plants at the end of the box near the
wall received much less light than those at the other end. They remained
there about five weeks and then were taken out and the plants set in the
open ground. During the five weeks box A, containing lots No. 1 and 2,
was changed, end for end, every day so that those two lots of plants
received nearly an equal amount of sunlight, but box B was not changed
so that lot No. 3, at one end of the box, was constantly near the walk
and in the full light, while lot No. 4, at the other end of the box, was
constantly near the wall and in partial shade. The effect on the growth
of the plants was very marked. The plants of lot No. 4 were nearly twice
as high, but with much softer stems and leaves than those of lot No. 3.
The plants received equal care when set side by side in the open ground
and at the time the first fruit was gathered seemed of equal size and
vigor, but the total yield of fruit of lots No. 1, 2 and 3 was very
nearly the same and in each case at the rate of over 100 bushels an acre
more than that from lot No. 4. This is but one of the scores of
experiences which have led me to appreciate, in some degree, the
necessity of plenty of sunlight for the best development of the tomato.

=Heat.=--The plant thrives best out of doors in a dry temperature of 75
to 85 deg. F., or even up to 95 deg. F., if the air is not too dry and is in
gentle circulation. The rate of growth diminishes as the temperature
falls below 75 deg. until at 50 deg. there is practically no growth; the plant
is simply living at a poor dying rate and if the growth, particularly in
young plants, is checked in this way for any considerable time they will
never produce a full crop of fruit, even if the plants reach full size
and are seemingly vigorous and healthy. The plant is generally killed by
exposure for even a short time to freezing temperature, though young
volunteer plants in the spring are frequently so hardened by exposure
that they will survive a frost that crusts the ground they stand in; but
such exposure affects the productiveness of the plant, even if it
subsequently makes a seemingly vigorous and healthy growth. Under glass,
plants usually do best in a temperature somewhat lower than is most
desirable out of doors. I think this is due to the inevitable
obstructi