418 ORIGIN OF LIFE IN AMERICA 



to be due to the greater antiquity of the grasses and sedges, 

 and he argues in favour of an ancient direct land connection, 

 long since disappeared, on which the slow southward advance 

 of these forms took place, the identical species having pre- 

 served their specific characters throughout a long series of 

 ages. This is precisely the conclusion I have come to in 

 regard to many species of animals of very wide range, con- 

 trary to the view generally held that most of such forms are 

 to be regarded as human importations scattered throughout 

 the world by commerce. 



I have mentioned on several occasions that California ex- 

 tended considerably further westward in former times, and 

 that the numerous little islands such as Guadalupe, Cerros, 

 Santa Catalina, Santa Eosa and others are the visible remains 

 of that ancient Pacific land belt. The fact that they are in- 

 habited by fourteen species and varieties of reptiles and 

 amphibians* not known from the mainland, suggests that the 

 islands have been separated from the latter since at any rate 

 pre-Glacial times. 



Now on the coast of Chile we have similar evidence o'f a 

 westward extension of land in former times. The tiny deer 

 known as the "pudu" occurs in Chile and Chiloe island. 

 Its only near relative lives in Ecuador. The small mouse-like 

 mammal Acodon brachyotis of Chiloe island and the Chonos 

 archipelago is peculiar to these islands, and so are many other 

 species of the lower groups of animals. There is, in fact, 

 quite a considerable assemblage of animals and plants on 

 these islands, indicating a former westward extension of the 

 mainland. Even the far distant Juan Fernandez island, 

 which lies five hundred miles from the mainland, possesses a 

 peculiar species of humming-bird (Eustephanus fernan- 

 densis) and no doubt other indigenous forms of animal life. 

 It is situated on the tract of the old land belt which I believe 

 to have once extended from the west coast of southern Chile 

 to south-western North America, and from there eastward 

 to Europe (Fig. 14). In early Tertiary times already parts of 

 this old land bridge had disappeared, so that Chile and south- 



* Denburgh, J. van, " Keptiles and Amphibians of Pacific Coast 

 Islands," p. 4. 



