WESTERN HEMISPHERE. 
3 
most beautiful flowers is more than we shall attempt, nor is it our 
province; the Dendrobiums and Vandas of the one are equalled 
by the Cattleyas and Oncidiums of the other, and so on through 
the list an equipoise may be found. As our illustration belongs 
to the western section, we propose to confine the following re¬ 
marks to the culture of that portion of the order, and having 
premised that each should be kept separate and treated distinctly, 
we shall reserve the other class till some future opportunity. 
The average temperature of Mexico, Guatemala, and other regions 
whence American Orchidacese are obtained, may we believe be 
stated at 60°, and this we have found to be a very safe mean from 
which to work in their management; *the variations on either 
side should not frequently exceed 10°; 50° being regarded as 
the minimum for the plants in winter, or when at rest, and 70° 
or at most 75° for their most active growth ; beyond this we would 
never allow the heat of the western house to ascend, without 
throwing it open on all sides to the exterior air. It may be well 
in this place to say something of the structures devoted to the 
culture of this tribe ; it was at first supposed, from the frequency 
with which they were met in the depths of forests and other se¬ 
cluded places, that an obscured light was necessary to them; in 
cultivation, however, experience shows that the erections for 
these as for all other plants cannot be made too easily accessible 
in every part to the life-giving rays of the sun, that an abundance 
of this primary agent of vitality may ever be present through 
our dull winters, ample command being secured over it, that the 
excess of summer may not be prejudicial; span-roofed houses 
are on this account to be preferred, and the glazing should inva¬ 
riably be done with the best glass, for irregularities in its surface 
by concentrating the rays in the manner of a lens, not unfre- 
quently disfigures the foliage of the plant beneath, at a time when 
only a comparative small amount of sunlight is observable. 
In the apparatus for heating the atmosphere of orchideous 
houses, provision should always be made for a supply of vapour, 
that a dry or moist heat may prevail as occasion requires, a gra¬ 
dual and continued escape of vapour among the plants when in 
an active state is every way preferable to the scalding effects of 
the rush of steam, obtained by syringing on the pipes in the 
usual manner, that it ought always to be thought of when the 
fitting-up is in hand. 
