HORTICULTURAL JOURNAL. 37- 
Other being fully understood, lie can control their action, so as to insure 
various developments conducive to the purposes he has in view. 
That the" plants exhibited at our horticultural meetings are so much infe- 
rior, in point of high culture, to those already mentioned, does not proceed 
so much from scarcity of talent on the part of practical men, as from a want 
of encouragement on the part of Horticultural Societies. It is a notorious 
fact, that plants showing superior cultivation rarely receive any more notice 
than the most ordinary collections. Nay, more, in some instances that have 
come under my personal observation, they have been silently passed and 
looked upon as innovations, while a promiscuous assortment of sickly stumps 
would receive high commendations for "great number and variety." I do 
not mean to enter further into this matter. It is enough to state the fact in 
connection with the present subject, so far as it refers to encouragement of 
talent in the production of exotic flowering plants. In referring briefly to 
the more essential requisites necessary to the perfect development of plants, 
we will notice in order the effect of light, the relation of soil and its modifi- 
cations, the influence of water, pruning, staking and shaping plants, and the 
operations intimately connected with the subject. 
Of all the agents of vegetation light is the principal, it is in fact the life- 
sustaining property; all other requirements may be secured, but in the 
absence of light no healthy growth can be made. The effects of continued 
darkness upon growing plants are familiar to every one. Leaves may be 
looked upon as the feeding points of the branches, as the spongioles are of 
the roots. All matter drawn by the roots for nourishment undergoes a 
transposition in the leaves. The processes of decomposition and elaboration 
in the leaves is due to the action of light, it is the mainspring of vegetable 
action, the power that operates the whole. 
It will be readily understood, therefore, that in cultivating green-house 
plants, the form and construction of the house will materially affect success. 
Single roofed houses, with opaque backs, are not fit to produce fine speci- 
mens, according to the interpretation of that term by practical gardeners. 
One-sided houses are productive of one-sided plants. We may occasionally 
see some enthusiastic in plant-growing elevating his embryo specimens on 
temporary platforms, with a view to securing "light on all sides," but 
although his attempts may be followed with success while the plants are 
small, large plants cannot be preserved in that healthful symmetry of growth 
when the light reaches them only on one side. 
For all purposes of plant culture double or span-roofed houses are 
