154 THE ORIGIN OF SPECIES 



chapter ou Geographical Distribution; for instance, the 

 fact of the productions of the smaller continent of Aus- 

 tralia now yielding before those of the larger Europaso- 

 Asiatic area. Thus, also, it is that continental productions 

 have everywhere become so largely naturalized on islands. 

 On a small island, the race for life will have been less 

 severe, and there will have been less modification and 

 less extermination. Hence, we can understand how it is 

 that the flora of Madeira, according to Oswald Heer, re- 

 sembles to a certain extent the extinct tertiary flora of 

 Europe. All fresh-water basins, taken together, make a 

 small area compared with that of the sea or of the land. 

 ^ /Consequently, the competition between fresh- water pro- 

 ductions will have been less severe than elsewhere; new 

 forms will have been then more slowly produced, and 

 old forms more slowly exterminated. And it is in fresh- 

 water basins that we find seven genera of Ganoid fishes, 

 remnants of a once preponderant order: and in fresh water 

 we find some of the most anomalous forms now known 

 in the world as the Ornithorhynchus and Lepidosiren, 

 which, like fossils, connect to a certain extent orders at 

 present widely sundered in the natural scale. These 

 anomalous forms may be called living fossils; they have 

 endured to the present day, from having inhabited a con- 

 fined area, and from having been exposed to leas varied, 

 and therefore less severe, competition. 



To sum up, as far as the extreme intricacy of the 

 subject permits, the circumstances favorable and unfavor- 

 able for the production of new species through natural 

 . selection. I conclude that for terrestrial productions a 

 \ large continental area, which has undergone many oscilla- 

 tions of level, will have been the most favorable for the 



