48 PHYSICAL DESCRIPTION O THE UNIVERSE. 



systematically-arranged catalogues, to which the too pompous 

 name of " Systems of Nature" was formerly given, present to 

 us an admirable connection and arrangement by analogies of 

 structure, whether completely developed, or (according to 

 views of an evolution in spirals) in the different phases passed 

 through in vegetables, by the leaves, bracteas, calix, blossom, 

 and fruit, and in animals by their cellular and fibrous tissues, 

 and their articulations or less perfectly developed parts. But 

 these ingeniously classified so called " systems of nature/' 

 do not shew us organic beings as they are grouped over the 

 surface of our planet, in districts, zones of latitude, or of 

 elevation, and according to other climatic influences arising 

 from general and often very distant causes. But, as we 

 have already said, the final aim of physical geography is to 

 recognise unity in the vast variety of phenomena, and by 

 the exercise of thought and the combination of observations, 

 to discern that which is constant through apparent change. 

 In the exposition of the terrestrial portion of the Cosmos, 

 we may sometimes find occasion to descend to very special 

 facts, but it will only be for the purpose of recalling the 

 connection existing between the laws of the actual distribu- 

 tion of organic beings over the surface of the globe, and the 

 laws of the ideal classification by natural families, analogy 

 of internal organisation, and progressive evolution. 



It follows from these discussions on the limits of different 

 sciences, and particularly from the distinction which it ia 

 necessary to draw between descriptive botany (morphology) 

 and the geography of plants, that, in the physical description 

 of the globe, the innumerable multitude of organised bodies, 

 which form so large a portion of the beauties of creation, 

 ought to be considered rather with reference to zones of 



