ORCHIDS. 27 
moderate amount of ventilatcrs along the apex ; bottom or 
side ventilation is unnecessary in such houses. 
Ferns,.— These may be grown well in almost any kind of 
house, if fairly low, close, and of a naturally moist rather 
than a dry nature, 
Orchids,—Before constructing a house for any particular 
class of orchid, a skilful expert in their culture had better be 
consulted. The temperate Odontoglots, such as the popular 
OQ. Alexandre, thrive best in a cool, airy, and lightly shaded 
structure, such as 
one suitable for A RAC MAS 
begonias or the i 
pretty little strep- 
tocarpus. The 
species men- 
tioned succeeded 
admirably, in the 
writers  expevi- 
ence, in a spaci- 
ous three-quarter 
span structure 
facing east, lightly shaded during the middle of the day only 
by some lofty trees growing near the southern end, but 
receiving the nearly full benefit of the sun in the morning 
and evening. Most of the dendrobiums will thrive in a low, 
warm, span-roofed structure running east and west, shaded 
on the south from powerful sun, and ventilated chiefly by 
means of openings arranged along the sides. For a large 
number of the more commonly grown orchids of an inter- 
mediate or temperate character, a well heated structure, such 
as that illustrated in Fig. 15, and suitable for bouvardias, 
