CHAPTER XII. 



BOTANY. 



A MONGST the very great difficulties in the way 

 ^- of studying botanical distributions, one of the 

 most serious is that he who puts forward either 

 theories or explanations does so only at the peril 

 of his reputation as a scientific botanist. The 

 wind of evolution has not yet stirred the dry bones 

 of systematic botany, and many are unable to 

 realise the main leading fact of evolution, namely, 

 that all genera and species of plants must have 

 had a definite origin in space. A species must 

 have either become differentiated in the particular 

 spot in which we find it, or it has wandered to that 

 spot from its original home. 



I do not think any field-botanist will quarrel 

 with the assumption that every particular species 

 is restricted to a definite climate, though the con- 

 ditions which a certain set of species (very limited 

 in number) require may be fulfilled throughout 

 very wide areas. 



The flowering season of any particular plant 



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