168 
THE GREENHOUSE. 
months, before the sun has attained the zenith of his power, and 
hence the benefit of a slight shade on all plant-houses ; for the 
great majority of our plants are either actively employed in the 
formation of fresh organs, or are displaying their floral treasures, 
just at the brightest part of our summer. To reduce the force of 
the mid-day sun is then highly beneficial, and the effect is in¬ 
creased by imparting to the atmosphere of the house a genial 
moisture, by means of water strewed over the floor, and a slight 
syringing of the plants in the evening ; and this may be continued 
with occasional variations to meet the fluctuations of the weather, 
until the approach of autumn, when it becomes necessary to 
admit the full influence of the sun among the plants, that each 
may have the requisite opportunity of thoroughly maturing its 
recent accessions, whether of leaves, branches, or fruit; and at 
this season many of them form the embryo of the flowers which 
are to give beauty to them in the succeeding summer. Without 
light, however, none of this can be done, and an abortive, un¬ 
fruitful growth is the only result. 
From what we have just said, the winter treatment will readily 
be guessed at. The altered condition of the plants then require 
that they be kept in a comparative inert state ; but though to the 
eye they appear completely inactive, there is little doubt that it 
is now that the accumulations of the summer are duly assimilated, 
and new vigour infused, to be developed in another season. Air 
and water supply to the plant, if not all, at least the principal 
part, of its food, the earth being correctly but little more than the 
medium through which the former are received; and, conse¬ 
quently, the management of the greenhouse may be shortly de¬ 
scribed thus. In spring give air and water moderately, increas¬ 
ing the quantity of both as the approaching summer draws near, 
when both should be supplied abundantly. Autumn treatment 
should be nearly identical with that of the spring, except that 
the increase should be in inverse proportion, and in winter the 
supply of moisture must be extremely limited ; air, however, may 
still be admitted whenever an opportunity is afforded by the ex¬ 
ternal atmosphere, as it has a tendency to counteract the injurious 
effects which an otherwise stagnant atmosphere might induce. 
With respect to the various manipulations required in an ex¬ 
tensive collection, let each be done as soon as required; the 
