98 THE ORCHID REVIEW. [APRIL, Igto 
Some new characters appear among the Epidendrez. One of them is that: 
of having articulated leaves, which is largely associated with the epiphytic 
habit, and Pfitzer suggests that the dejection of the laminaof the leaf probably: 
arose as a means of diminishing the evaporating surface in times of drought.. 
It isnot found in the Diandre, Neottieze or Ophrydez; and is not universal 
among the Epidendree. The production of secondary stems from the: 
rhizome, and the thickening of the internodes into variously shaped pseudo- 
bulbs, as well as the modified structure seen in the aérial roots, by which 
they cling to the bark of trees and become covered with:a protecting sheath 
of velamen, are necessarily adaptations to fit them for an epiphytic mode of 
existence. The production of additional partitions in the anther, by which. 
the pollen-masses are sometimes divided into eight more or less. distinct 
lobes is possibly connected with the economy of fertilisation, but has. 
apparently arisen independently in different groups, for some closely allied 
genera differ inthe number of the pollen masses, as. Cattleya and Leelia,. 
Octomeria and Pleurothallis, &c. 
Another very curious character is the production of a distinct foot to the 
column, from the apex of which the lip arises, and.to the sides of which the 
lateral sepals are often affixed, producing what is called a mentum or chin,. 
as in Dendrobium. This modification is also connected with the economy 
of fertilisation, and probably bears a definite: relation. to the fertilising insect.. 
Just as the column is an elongation of the disc of the flower, and its. 
production is correlated with a reduction of the filament of the anther, so 
the foot is a further unilateral extension of the disc, which carries up the 
lip with it, and frequently the lateral sepals also. The foot varies greatly in 
detail, sometimes even in the same group, and probably arose independently 
in different groups, being found also in some of the Vandez. It is often 
found in combination with an articulated or mobile lip. 
The Epidendrez, as now understood, form a very large tribe, and we’ 
may now indicate a few of its sub-divisions and some of the principal 
genera. Anything like a complete account would require much more space: 
than can be spared, and many of the details are not yet worked out. The 
group was divided by Bentham into nine subtribes,. but without any attempt 
to indicate their progressive development. It is not easy to fix the precise 
starting point of the Epidendrew, and some of the early types are not 
imprcbably lost. Both Bletilla and Thunia were considered by Reichenbach 
as belonging to Arethusee, but they had been previously included in 
Bletia and Phaius respectively, to which they were returned by Bentham.. 
The genus Elleanthus, which is not often seen in cultivation, is placed by 
Bentham in the subtribe Coelogynez, while Pfitzer puts it near to Sobralia,. 
and although the system of the latter author is largely based upon vegetative: 
characters, the position in this case seems to indicate better the ee of. 
