20 ORCHIDS. 
which the Order is so remarkable, and if not as strikingly 
beautiful are by no means to be despised, even from an 
ornamental point of view. 
The knowledge of Orchidacee has grown during the last 
fifty years at a rate quite disproportionate to that of the 
rest of the Vegetable Kingdom. Linnzus only knew about 
a dozen exotic Orchids, and stated his opinion that the 
world, when fully examined, might probably yield as many 
as a hundred species. Now, at least 2500 are known to 
English horticulturists, while the number of species in the 
Order is estimated at 6000! 
In colouring, as in odour, Orchids display an almost end- 
less variety. Their rarest colour is blue, which, indeed, is 
almost unrepresented in collections—save, perhaps, in Vanda 
cerulea—although many purples in which blue _pre- 
dominates may be found. Several terrestrial Cape species, 
however, produce flowers of an intensely sky-blue colour, 
one of which was on this account appropriately named 
Herschelia czlestis by Lindley, in honour of Sir John 
Herschel, the astronomer. In one or two genera it 
is the leaves rather than the blossoms which attract the 
horticulturist, as in the case of the exquisite species of 
Ancectochilus and Goodyera, the rich green or purplish 
leaves of which are traversed by a beautiful network of 
gold or silver veins. Some species of Phalznopsis and of 
Cypripedium have prettily-marked foliage. On the whole, 
however, the Orchid family is conspicuously wanting in 
species with ornamental foliage. 
The odours of Orchids are most diverse, varying even in 
the same species at different stages of its existence. Some 
have an especially delicious and almost overpowering 
fragrance, such as Aérides odoratum and Epidendrum 
aromaticum. Mr. Bateman enumerates only a few of the 
various odours which they represent when he likens the 
