in Geographical Botany, 499 



other subdivisions will immediately strike us; founded, not, 

 like the former, on physical causes, but on the character of 

 its vegetation. Here, then, our labours commence ; this is 

 the point where we register the leading features of its flora, 

 and where our pursuits leave those of the geographer. For 

 illustration, we will take Asia. Over its vast surface are spread 

 several large masses of vegetation, each in its intensity pre- 

 senting distinct well-marked features, but, when approaching 

 its neighbours, imperceptibly shaded off into them ; those more 

 separated presenting appearances well defined, and impossible 

 to be mistaken. Thus, the Siberian flora differs much from 

 the Indian ; for they are widely separated, and controlled by 

 very different physical causes ; whilst those which approach 

 each other are often so similar as to make it questionable 

 whether their individuality is correct. The Tartarian flora 

 has many characters common to the Siberian; and it is ques- 

 tionable if the Malay should be separated from the Indian. 

 Our object is to establish satisfactorily these divisions ; and, 

 having done so, they may be defined on the map by different 

 colours : the taste of the naturalist leading him to adopt those, 

 which seem to speak most to the mind of the nature of the 

 vegetation. 



If the soil should possess sufficiently distinct characters to 

 be worthy of record, its varieties might be easily separated by 

 dotted lines, running according to their distribution, and 

 named in full at the point where they leave the traced outline 

 of the map, or in any other convenient situation. 



We now come to the more definite portion of our la- 

 bours, and shall find ourselves much entangled by numerous 

 names and observations, all to be crowded into a very con- 

 fined space. Here every means must be adopted to convey 

 as much information as possible by the fewest characters. 

 The natural families have first to be settled ; and to each of 

 these should be attached a sign expressive of the other divi- 

 sions of the world to which it may be common. Figures, at 

 first, struck me as being the most likely to answer this end ; 

 but, on farther reflection, I thought it best to assume some 

 form to which the eye was accustomed, some parts of which 

 Jig. 46. might be removed, without taking away the im- 

 pression of its original shape. The circle seemed 

 to answer admirably for this purpose, divided into 

 l /^\ 3 six parts, in the manner represented inj^. 46. ; 

 6 .,\^~yC 4 one to four, or even five, parts of which might be 

 ^5 removed ; and the remaining would still show the 



station it occupied in the original figure. Com- 



