322 ORCHWACEjE. [chat. 



ground but upon the trunks of trees. They do not, how- 

 ever, attach themselves to the tree upon which they grow ; 

 they are not parasites preying upon its juices, like the 

 Mistletoe and Loranths, referred to at p. 223. Such plants 

 are distinguished as epiphytes. They throw out cord-like 

 adventitious roots freely, and the lower joints of their stems, 

 in many genera, become much thickened and fleshy, so as 

 to resemble bulbs, suggesting the name pseudo-bulbs, which 

 is specially applied to them. 



Very few species of this great Family are of any economic 

 importance, though large numbers are prime favourites with 

 cultivators in Europe, from the beauty and singularity of 

 their flowers. 



As representing a distinct Tribe of the Orchid Family, 

 take any species of Ladies' Slipper ( Cypripedium\ character- 

 ised by two anthers, one on each side of a shield-like 

 central disk regarded as a rudimentary 

 anther (corresponding to the single 

 anther which is present in all other 

 Orchids). The column in the Ladies' 

 Slipper projects over the opening into a 

 large, slipper-shaped, hollow labellum. 

 The pollen -grains, unlike those in the 

 Orchids described above, are not con- 

 nected together into poUinia, but they 



Fig, 208. , Column of ^16 COatcd with a viscid fluid, which en- 

 Ladies' Slipper. ables the grains to adhere when rubbed 

 against the stigma, which in Cypripedium is not viscid as 

 in other Orchids. 



A small Family, the Apostasieae, nearly related to the 

 Orchids, is confined to India. It serves as a link con- 

 necting the anomalous structure of Orchids with that of 

 Monocotyledons generally, differing from the former in 



