THE ORCHID FAMILY. 



185 



the genus Gatasetum the caudicle is in the form of a strap, 

 which is highly elastic; on being touched, or the parts of 

 the flower disturbed, it springs out with a degree of force to 

 the distance of a foot or more, carrying with it the pollen and 

 gland, the latter adhering to whatever surface it strikes 

 against; instances are known of its striking the face, causing 

 dismay to unwary observers. 



The labellum of some species is attached as it were by a 

 fine hinge, the least motion causing it to vibrate. In Bolbo- 

 phyllum harhigerum it consists of a tuft of brown, nearly erect 

 hairs, like a little brush, the least motion of the air causing it 

 to bend down, but quickly regaining its position, giving the 

 idea of nodding or bowing, and it does this by the motion of 

 the breath in speaking at a yard or more distant, and many have 

 been deceived by the idea that it was voluntarily bowing to 

 them. This motion is, however, only mechanical, and quite 

 different from the sensitive motion of the lip of Pterostylis. 



I have now stated sufficient to show the curiosity of orchids, 

 which will be found verified on reading Mr. Darwin's book 

 lately published on the " Fertilization of Orchids." 



A family very nearly related to the orchids, is Aposta- 

 siaceas — a group of perennial plants of which there are 

 said to be 5 species, natives of India. 



Another family, Burmanniace£B, consists of about 30 

 species, being small perennial plants, natives of the tropical 

 parts of both hemispheres. 



Also we may here notice a small group of curious plants 

 — Triuridacese, consisting of about 8 species, natives of 

 Brazil, Ceylon, and Java. They are small translucent peren- 

 nial plants, with simple, erect stems and pale leaves, destitute 

 of nerves. Flowers minute, on spikes or racemes. They 

 are only interesting botanically. Botanists entertain different 

 views of their relationship; some place them with Bur- 

 mannia, which is also of doubtful affinity. 



