ENDEMISM 65 



conditions of life. It is quite possible that relict endemics, 

 through the earlier invasions of the original species, may be 

 found in a place in which the latter did not arise : in conse- 

 quence, there are endemics which have arisen in their 

 present area, and those which have migrated to it. The 

 latter may often be further modified, and would then fall in 

 the first class. The author has further pointed out that the 

 concept of endemism varies with the size of the area, and 

 that it is inapplicable to political divisions, except when 

 these have natural limits. Delpino (1898:356) emphasized 

 the primary importance of endemism in regional limitation, 

 and considered the relative meaning of endemism in groups 

 of various rank and in regions of different extent. Poand 

 and Clements (1900:53) extended the concept of endemism to 

 cover vegetation, in such a way that one may distinguish 

 Tegetation elements, e. g., endemic formations, as well as 

 floral elements. 



Since its first use by DeCandoUe, the term endemic has been 

 employed quite consistently by phytogeographers with the 

 meaning of "peculiar to a certain region. " Some confusion, 

 however, has arisen from the fact that a few authors have 

 made it more or less synonymous with indigenous and auto- 

 chthonous, while others have regarded it as an antonym of 

 exotic. In its proper sense, endemic refers to distribution, 

 and not to origin. Its exact opposite will be found then in 

 Fenzl's term polydemic, dwelling in several regions. Indi- 

 genous (autochthonous) and exotic, on the contrary, denote 

 origin, and are antonyms, indigenous signifying native, and 

 exotic, foreign. As Drude has shown, endemic plants may 

 be either indigenous, as in the case of those species that 

 have never moved out of the original habitat, or exotic, as 

 in the much rarer instances where a polydemic species has 

 disappeared from its original home and from all regions into 

 which it has migrated except one. It is understood that not 

 all indigenous or exotic species are endemic. The proportion 

 of endemic to polydemic species is a variable and somewhat 

 artificial one, depending upon the size of the divisions 

 employed. 



