PT. II, CH. XV] ENDEMISM AND DISTRIBUTION 149 



and mountain chains (if over 4500 feet), besides all more or less 

 isolated pieces of country, like Italy, possess endemics. They are 

 also frequent in such localities, even in large areas of country 

 with large populations of plants, as are isolated in the sense that 

 they do not lend themselves to free interchange of plants with 

 their surroundings. Such are stations in large forests, or patches 

 of grassland in forest country, patches of country with salt soil, 

 and the like. The numbers and proportions increase to the south- 

 wards (and the isolation becomes less marked), till one finds the 

 maxima in such places as ^yest Australia, South Africa, Juan 

 Fernandez, the Mascarene Islands and New Caledonia. Beyond 

 about 40° to 48° S. they fall off again. "The greatest concen- 

 tration of species in small areas occurs in... West Australia and 

 South Africa" (52, p. 36). "The fertile portions of New South 

 Wales, Victoria, South Australia, and ^Vest Australia do not 

 probably... exceed in area Spain, Italy, Greece, and European 

 Turkey, and contain perhaps half as many more flowering 

 plants" (55 b, p. xxxi). 



Endemism, though it is most commonly associated with 

 islands in people's minds, is by no means a phenomenon con- 

 fined to them. It is very strongly marked in comparatively 

 isolated mountains, such as Kilimandjaro (and cf. 117 and 122), 

 and in mountain chains, and in these cases the flora presents, as 

 a general rule, less relation to that of the plains than does the 

 flora of an island to that of the nearest mainland^. This may be 

 largely due to the fact that, as explained upon p. 37, mountains 

 may act as highways of migration for the plants of other coun- 

 tries and climates. 



Endemism is also strongly marked upon continental areas, 

 and while the maximum proportion is in West Australia and 

 South Africa — regions where conditions are rather extreme — all 

 the southern land masses, more especially, show a great pro- 

 portion of their species confined to themselves. 



Whilst the largest numbers and jDroportions of endemics are 

 chiefly in the more southern countries, there are also large 

 numbers and proportions in several of the northern, e.g. in 

 Mongolia, California, the region about the Mediterranean Sea, 

 etc. There are a few endemics on the west coast of Europe, the 

 Alps contain about 200, and Italy about the same; and the 



1 "A great deal too much has been made of the assumed extreme differen- 

 tiation exhibited by insular floras as compared to the continental flora" 

 (52, p. 387). 



