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very few epiphytal orchids occur anywhere within the temperate 

 regions. 



The exact reverse is the case with the epiphytal orchids. They 

 are essentially a tropical group of plants. They have doubtless 

 become epiphytal in the struggle for existence. In the dense forests 

 of the tropics there is no light for terrestrial orchids and they have 

 betaken themselves to the trees and bushes, in the forks and angles 

 of whose boughs the seeds germinate and thrive. There are genera 

 which are partly epiphytal and partly terrestrial, such as the genus 

 Catasetum, some of whose species "live on the sand reef, others 

 growing on low trees in the swamp, and one which has found a 

 congenial home among the leaf-stalks of the eta palm " (vide Rodway, 

 "In the Guiana Forest"). Such a combination of habitats is to be 

 found in the Guianas ; while in N.E. Peru, about the headwaters 

 of the Amazonian tributaries, there has recently been discovered the 

 wonderful Onridium leopoldi, which begins by being a terrestrial 

 plant, and when it has grown several feet in length throws out aerial 

 roots and half becomes a creeper, yet the roots do not attach them- 

 selves to other plants. Up in the mountains where forest growths 

 have given place to scrub, orchids are found on these low bushes 

 comparatively near the ground, and where large rocks and boulders 

 exist, especially near streams, these also form an anchorage for epi- 

 phytes. In the Philippine Islands is to be found that great rock- 

 loving genus of orchids, Phalcenopsis, and it is questionable if these 

 plants derive any other means of sustenance than light, air, and 

 moisture. It has been proved over and over again by many orchid 

 cultivators that some species of this and other genera will, if hung 

 up by a plain wire in a moist but light and airy glasshouse, grow and 

 thrive for years, and even throw healthy flower spikes without any 

 other attention than watering. It is probable that many terrestrial 

 orchids growing in very poor soil obtain but a very scanty sustenance 

 from the earth and only derive a more or less constant moisture to 

 the roots. There are terrestrial orchids, however, that do require a 

 richer soil, and it is reasonable to suppose that some benefit other 

 than moisture is derived therefrom. The genus Cypripedium and its 

 allies is a good example, and Disa might also be cited. The terres- 

 trial orchid has the great difference in its root action from the 

 epiphytal, that whereas the former has only to obtain nourishment 

 through its roots the latter has at the same time to use its roots to 

 cling on to the place it has selected to live on, as well as to obtain 

 its necessary nourishment through them. Some orchids throw out 

 a comparatively few large fleshy roots, while others throw out 

 immense numbers of thin fibrous roots. 



In the case of some of those that throw out large fleshy roots, 

 Nature has devised a means of protecting them against the attacks 

 of cockroaches and other depredators, by making the orchid mass, 

 or sometimes the hollow bulbs, the home of ants. In Trinidad 

 Diacrium bicornutum, an orchid with large yellow bulbs, grows in 



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