158 
THE FLORIST’S JOURNAL. 
instance, we have only to treat of tropical plants, and therefore 
need not extend our remarks be} 7 ond the latitudes in which 
they are found; it may be well to mention another important 
matter connected with their geographical distribution, affecting 
their cultivation most materially; this is the difference which 
exists in the state of the atmosphere at different altitudes. 
The effect of elevation is to cause a reduction of temperature 
and rarefaction of the surrounding air; the latter produces an 
increase in the intensity of light, and, of necessity, a corre¬ 
sponding decrease of humidity. Now, though Orchidaceous 
plants inhabit only those places where moisture is prevalent, at 
least for a season, and consequently are seldom found at very 
considerable elevations, still a degree of difference is observable 
among them of sufficient extent to render attention to these cir¬ 
cumstances absolute and indispensable.” 
Then, again, in Sect. 2., treating of the benefit of two or 
more houses, the following passage occurs, — the “absurdity” 
of which we confess to have been unable to find. “ Orchi¬ 
daceous plants, being natives of tropical regions, require, in 
their cultivation, what is technically termed a seasonal treat¬ 
ment; that is, a period of active growth, and one of decided 
rest; during the former, which agrees with the rainy season of 
the country of which the plant is properly an inhabitant, every 
stimulative means that the cultivator possesses should be ap¬ 
plied to the encouragement of a vigorous and full development 
of the several increasing parts of the plants ;*and after the com¬ 
pletion of this seasonal growth, the period of dormancy or rest 
should be brought on gradually, when all excitement must 
cease, in order to give full maturity to the newly-developed 
organs. Now, as it happens that Orchidaceous plants are 
obtained from many and various climates and seasons, it is not 
reasonable to expect, when we take the force of natural habit 
into consideration, that they will, all of them, begin to grow at 
one and the same period, bloom at the same time, or rest alto¬ 
gether at one season ; not even if we endeavour to assimilate 
these seasons to those of our own climate ; there will always 
be a number of them, in a collection of the least pretensions, 
that will be springing into activity, and requiring excessive 
moisture, and other stimulants ; while another portion will be 
speedily advancing to maturity, and consequently demanding 
for their future welfare quite a contrary treatment; and a third 
