v.] REMARKABLE LEAVES. 87 
perish on being brought into the lower and warmer 
zones. One species is known as the Butterfly Orchis 
(Oncidium papilio) from the appearance of its flowers. 
The clusters—or panicles—of flowers are in some 
species of an enormous size; in more than one species 
they reach the length of twenty feet, whilst the flowers 
themselves are three inches across. FPeristeria elata, 
a Central American species, is locally known as “ El 
Spirito Santo,” from the resemblance of the column 
and its appendages to a dove. 
In the genus Catasetum there is a peculiar contriv- 
ance to effect cross-fertilisation. In this species the 
column bears at about its middle two long sensitive 
projections, to which Mr. Darwin has applied the 
term antenne. The labellum, or lip, is thick and 
fleshy, and the bees visit it in order to gnaw its 
edges. In so doing they touch the antenna, which 
transmits a vibration “to a certain membrane, which 
is instantly ruptured; this sets free a spring, by which 
the pollen mass is shot forth, like an arrow, in the 
right direction, and adheres by its viscid extremity 
to the back of the bee. The pollen mass of the male 
plant (for the sexes are separate in this orchid) is 
thus carried to the flower of the female plant, where 
it is brought into contact with the stigma, which is 
viscid enough to break certain elastic threads, and 
retaining the pollen, fertilisation is effected.”—Dar- 
win, “ Origin of Species,” p. 155. 
More remarkable still in this connection is the 
extraordinary contrivance in a species of orchid 
called Coryanthes, lately described by Dr. Criiger and 
referred to by Mr. Darwin, from whom we quote the 
