302 VON MARTIUS ON STOVE CULTIVATION. 
the South, and also the East and West ; for, reflected light acts more 
powerfully than direct, the greater the angle of incidence of its rays. 
6. If it is found desirable to apply glass extensively on the north- 
side, this important result will be attained, that it will contribute to- 
wards maintaining as uniform a degree of heat within as possible (by 
preventing its accumulation in the higher strata of air), and promoting 
transversal currents. : 
7. In both the one and the other description of buildings, it is par- 
ticularly to be attended to, that shade-plants are kept entirely apart from 
others; if in the same house, they require distinct treatment. 
8. The plants which belong to the Stove-Conservatory are those, pe- 
culiar to the forest vegetation, both the loftiest and ordinary, of their 
native country ; and as the denseness of a forest impedes the full deve- 
lopment of its trees, so does the same happen in a crowded house. 
Hence the area must be proportionate to the production of branches 
and leaves. That those structures are in many cases overloaded with 
plants, is proved by the practice of removing many of these out of doors, 
into the open air, in summer; the remnant being mostly numerous 
enough to occupy the entire space, without preventing commodious ac- 
cess, 
9. The more spacious the building is, the greater opportunity does 
it afford, for cultivating also plants which thrive under considerable 
privation of light; that is to say, such of these, as are kept irrespec- 
tively of their flowering, or which may be accommodated with light at 
that particular period, or else are accustomed to blossom in the shade. 
10, The organization of trees fits them in a greater degree than 
plants of lower stature, to have the loss of light compensated by an in- 
crease of temperature in the soil; and they demand, accordingly, espe- 
cial care in that respect during the season of the year, when the scanty 
supply of light indicates a judicious and cautious increase of bottom- 
heat in the building. 
11. Since the forest-vegetation is, on the whole, more dependent on 
periodical light, than the ground-vegetation, it follows, that we must 
employ a variety and complication of appliances, in order to modify the 
effect of light and shade, which are less indispensable in the low houses 
(propagating stoves) where herbaceous and the like plants are chiefly 
and extensively cultivated. 
12. These last-mentioned buildings and plants ought to have as 
