GEOGRAPHICAL DISTRIBUTION OF PLANTS 335 



c-nginated? If this were so, we might assume that their 

 fitness for their present life-conditions has been acquired by 

 Means of adaptation. If not, there is no reason at all for 

 explaining their characters on the basis of this principle, and 

 ail speculations of this kind are reduced to mere hypotheses, 

 lacking even the possibility of comparative or experimental 

 evidence. 



The current conception tacitly assumes that all or nearly 

 all living beings originated on the very spots where they are 

 now found, or, at least, under quite similar conditions. It 

 is evident that only on this assumption the causal connec- 

 tion between environment and characters can help us in ex- 

 piaining the latter. The present life-conditions are called 

 upon to explain the observed instances of fitness in plants. 



If, however, plants have as a rule migrated from their 

 native spots, then they are now found in environments which 

 have no right whatever to be considered as the cause of their 

 characters. Quite on the contrary, the migration and the 

 dispersion must have been guided by the nature of the species. 

 Or, in other words: Each plant must have sought out the 

 conditions where it could thrive best on account of its given 

 peculiarities. 



Thus we come to the conclusion that the relation between 

 organisms and their present environment is quite the reverse 

 of what it is commonly assumed to be. The properties of 

 the animals and plants must be considered as given facts, 

 and on the basis of these their present distribution is to be 

 explained. It is readily granted that this proposition only 

 withdraws the main point from our study, but on the other 

 hand it brings the investigation along a- path of direct 

 inquiry and experience instead of imperfectly founded 

 speculations. 



From this point of view the geographical distribution 

 of plants and animals must be discussed under two different 



