Nature mid Habits of Orchids. 93 



below the freezing-point, and where the leaves are covered with hoar-frost. 

 Thus the different species demand far different treatment ; and from 

 ignorance of these requirements and peculiarities have arisen many of the 

 failures which have hitherto attended their culture. 



A high, mean temperature throughout the year, and a climate either 

 constantly humid or at least periodically so, are atmospheric elements 

 eminently favorable to the production of these plants. All those species 

 which simply exist by clinging by their roots to the branches of growing 

 trees, and probably other species, must derive necessarily their nourishment 

 in a great measure, if not entirely, from the moisture in a very elastic state 

 that surrounds them. And although Nature seems, in general, to have pro- 

 vided for the scantiness of their food by the construction of them with a 

 cuticle capable only of parting by slow degrees with the fluid they receive 

 by their roots, yet it is obviously requisite that they should be so situated 

 as to be within reach of an abundant supply, not only at the time when 

 they are growing, but, to a certain extent, at other periods. Thus we find 

 that the hottest countries if dry, and the dampest if cold, are destitute of 

 them ; while there is no instance of a country both hot and damp where they 

 are not plentiful. It may, however, be remarked, that the terrestrial orchids 

 will bear a far greater degree of cold and drought than the epiphytal 

 species ; their range is therefore much greater : and the general remarks 

 about orchids must be taken with a great degree of allowance in respect 

 to this class. 



Notwithstanding the high temperature of Africa, they are unknown in 

 the sandy deserts and parched atmosphere ; yet they abound in Sierra 

 Leone, where the climate is damp, and are not unfrequent in the jungles 

 at the Cape of Good Hope. 



In the ^Vest-India Islands they exist in great quantities, particularly in 

 Jamaica and Trinidad ; not, however, so much on the coast as on the lower 

 ranges of hills. 



At Rio Janeiro, the mean temperature is 74° 3', and much higher inland; 

 the woods are so damp, it is impossible to dry plants ; and, in such situations, 

 multitudes of orchidaceous plants occur. In the immediate vicinity of 

 Buenos Ayres, however, where the mean temperature is 67° 6', and the air 



