4 



INTRODUCTION. 



so-called region of palms, the longitudinal range of which is the most extensive, 

 would seem to be on that account the richest in species as well as in peculiar 

 features. How interesting would prove the contrast between three views repre- 

 senting respectively an East Indian, an African, and an American virgin forest, as 

 nearly as possible having the same soil and climate ! Without doubt there would 

 be in all three much physiognomic resemblance, notwithstanding the total differ- 

 ence of their component elements. What in the one would only be indicated, 

 would in the other have obtained full development. Thus climbing plants play a 

 more important part in the physiognomy of the Indian jungle than in that of 

 the American forest, whilst the latter enjoys the advantage of harbouring a greater 

 number of strange and beautiful epiphytes. Here then the difference between the 

 continents, totally disappearing towards the poles, is most evident. 



It is unnecessary to mention that these differences stand in the same relation 

 towards those of the geographical latitudes, as the species do towards the genera, 

 and that, as a rule, only allied species or forms represent each other in the different 

 longitudinal divisions of one and the same zone.* The facility with which almost 

 all species may be transplanted from one of the longitudinal divisions into the 

 other, though a well-known fact, should be noticed as tending to prove more than 

 all others that the longitudinal differences are essentially independent of climate, 

 and not caused by certain subdivisions of it. The law according to which one part 

 of a zone originally produces this, the other that form, does by no means preclude 

 interchange of species, and it would almost seem as if Nature had originally 

 adopted that mode of distribution in order to show even here its tendency towards 

 diversity. The transition being, generally speaking, only gradual, it would be 

 difficult to find in all cases for the various physiognomy of plants a well-defined 

 boundary line. Still Nature has bestowed on every part of our earth's surface 

 which we geographically may term " country " peculiar beauties, by which it 

 may be known as readily as one organic being from another. Without this 

 higher significance the chequered masses, which would otherwise appear less 

 noteworthy, become important objects of science and the art subservient to it. 

 True, the latter has no slight problem to solve. Not only is travelling in far- 



* Of course in allied species there is a certain related to the Lobelias, strikingly recalls the Yuccas 



resemblance in form, but very often the type pre- of the higher mountains of America situated in the 



scribed as it were to a certain climate, selects, in the same latitude. In the extreme east of the Old 



different longitudinal divisions, plants belonging to Continent this form is represented by screw-pines 



widely different families. To cite one instance : the (Pandamis), having a single crown supported on an 



mountain plant from Simen, figured and described erect trunk, 

 by Kuppel in his "Abyssinian Journey," though 



