I. PHYTO-GEOGRAPHY. 373 



In practice, the distinction cannot be very clearly or fully 

 kept up ; one department passing into the other almost 

 imperceptibly. For instance, a local Flora enumerates 

 the plants of some one particular place or country, 

 whether a natural or a political division of the earth's 

 surface. Two or more such Floras afford data for com- 

 paring the botany of separate portions of the earth, and 

 for tracing out any floral characteristics by which those 

 portions resemble or differ among themselves. In this 

 respect, the Floras and their contents should class under 

 the division of botanical geography. Again, local Floras 

 also record the special places and census of their included 

 plants, and usually show whether the species are partially 

 or generally spread within the area, with other local con- 

 ditions under which they are found. In this view, the 

 same books may be said to treat about geogi'aphical 

 botanj\ 



Practically, the two artificial divisions of the general 

 subject continually thus glide one into the other, and are 

 closely commingled in books. Nor, indeed, are they 

 always defined in the same decided manner as here done. 

 Among the latest distinctions are those by Alphonse 

 De Candolle, who condenses the definitions into titles for 

 his second and third 'books'; the first 'book' being 

 devoted to a special hobby of the learned Botanist. His 

 divisions run thus, apart from the titles of subordinate 

 chapters: — " 1. Geographical Botany, or considerations 

 on species, genera and families, from the geogTaphical 

 point of view. — 2. Botanical Geograj^hj^, or considerations 

 on the various countries of the earth from the point of 

 view regarding the vegetation which covers (re-couvre) 

 them." It does not appear that the prefixed syllable, in 

 the verb quoted, is intended to have any sj)ecial signifi- 

 cation, different from that which is expressed by the 



