ORCHIDACEOUS PLANTS. 307 
growing point surrounded by scales, and constituting a leaf-bud 
when at rest, which eventually grows into a sccondary stem or 
branch in which leaves and flowers are developed. This kind of 
stem develops every year a lateral bud with a tubercular root 
attached, which, after unfolding its flowers-and ripening its fruit, 
perishes, to be succeeded by the stem belonging to the lateral 
bud; hence the species having this kind of stem has always a 
pair of tubercles attached, one shrivelling and in process of 
exhaustion, the other swelling and progressing towards completion. 
The leaves are uncertain,—usually they are sheathing at the base, 
and membranous; but in Vanilla they are hard, stalked, articu- 
lated at the base, and have no trace of a sheath. Sometimes they 
are leathery and veinless, frequently they are membranous and 
strongly ribbed, especially in Maxillaria and Cypripedium. 
“The floral envelopes are constructed upon a ternary type, and 
consist of three exterior and three interior pieces, the exterior 
ing nearly equal, but less brilliantly coloured than the interior, 
but the two lateral ones are often of a somewhat different form 
from the other, which is anterior when young, but becomes posterior 
when the flower expands, in consequence of the flower-stalk 
ming twisted or curved. 
“The centre of the flower is occupied by a body called the 
Colusan, which is formed by consolidation of style and stamens, of 
which there are, in the greater part of the order, only one present, 
which igs placed opposite the intermediate sepal, and, consequently, 
alternate with the petals, but in Cypripedium there are two sta- 
Mens. In the greater part of the order a single anther terminates 
the column. This is usually two-celled, but often has its cells divided 
Into two or four other cavities by the extension of the Endothecium 
between the lobes of the pollen-masses, or it is occasionally 
More or less completely one-celled by the absorption of the con- | 
nective,” 
. The pollen consists of lenticular or spheroidal grains, either 
— Single or cohering in pairs, threes, or fours, or in larger masses in 
indefinite numbers ; usually held together by an elastic filamentous 
_ _ Stance, which either contracts on adhesion with a gland origi- 
2 Rating on the margin of the stigma, as in Ophrydea, Neottiew, 
- Vandee, or it is folded — the pollen-masses, as in 
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