CH. XV] ENDEMISM AND DISTRIBUTION: SPECIES 165 



portion of its genera endemic than have the outlying islands, 

 etc. The average size of all 52 is 52 species, or still much larger 

 than that for the world, though less than for New Zealand. 



The further out one goes from the centres of greatest massing 

 of genera and species, in other words, the larger on the average 

 (in size in the world) do the non-endemic genera become. The 

 genera above mentioned in the Hawaiian Islands, New Zealand, 

 and India, that are below the average world size, are in all 39 

 with 89 endemics, while those above are 117 with 688. This fits 

 in with what was said above (p. 115) about Size and Space, that 

 on the whole the larger the genera, the larger the area they 

 occupy. 



This fact, that the endemic species, in all regions of the world, 

 belong in greater proportion, not to the small and local genera, 

 but to the large and widespread, is one of the most striking 

 features that spring to attention when one begins to study 

 endemism. In New Zealand, for example (37), the genera that 

 have most endemic species are Ranunculus'^ (with 32), Epilohiuni 

 (24), Coprosma'^ (40), Olearia^ (35), Celmisia^ (42), Senecio^ (29), 

 Myosotis (21), Veronica^ (81), Carex'^ (36) and Poa^ (21), a fairly 

 well-known list of genera. These ten contain no less than 36 per 

 cent, of the endemics of New Zealand. Or in Ceylon, the largest 

 numbers of endemics are in Eugenia (29), Memecylon (21), He- 

 dyotis (16), Symplocos (17) and Strobilanthes (25), again not 

 altogether unknown genera, the five containing 13 per cent, of 

 the endemics of the island. And if one study the endemic or 

 local species of the world, one finds these same genera appearing 

 in many other places with large numbers of local species; Eu- 

 genia, for instance, has about 240 in Brazil (52 in the little state 

 of Rio). If one adopt the explanation of dying out, these great 

 genera must have become world-wide very early, and have left 

 all these endemics as stragglers, dying out before the advancing 

 host of those species which had proved the best adapted to the 

 conditions. 



The view to which all this leads is simply, as has already been 

 mentioned (p. 61), that in the vast majority of cases endemic 

 species are young species comparatively recently evolved, and 

 still in the earlier stages of their distribution about the globe, 

 Mhile they show no points of distinction from species of larger 



^ These genera also oeciir with endemic representatives on the outlying 

 islands (Kermadecs, Chathams, Aucklands), where they have 27 out of the 

 grand total of 73 endemics of these islands, or 37 per cent. 



