14 FOOT-NOTES TO EVOLUTION. 



uniformity of type is accounted for. But what of the 

 difference of species ? If change of conditions may on 

 the islands cause great and permanent changes in a spe- 

 cies so as to transform it into a different 



o species species, may not the same change take 



change with , , , ^ ,r • , 



, place elsewhere ? May it not happen on 



the mainland as well as on the islands? 

 And if on the mainland, what guarantee have we of the 

 permanence of species anywhere ? May they not be con- 

 stantly changing ? May not what we consider as a distinct 

 species be only the present phase in the changing history 

 of the series of forms which constitutes the species ? 



The other phase of the problem which was presented 

 to Darwin was that of the succession of fossil and re- 

 cent mammalia, especially the edentates 

 The species of (ant-eaters, armadillos), etc., in South 

 South American . . lu- r- i • i 



, . . America. We find in the extinct species 



edentates. '^ 



the same peculiarities of structure that 

 we see in the forms still living. These peculiarities are 

 not shown by animals either recent or fossil in other 

 parts of the globe. If each of these species has been 

 an independent creation, by what law should the re- 

 cent forms duplicate the peculiarities of the extinct 

 forms ? Is the process of creation in some way influ- 

 enced by the peculiarities of forms which have pre- 

 ceded these in the same region and not by forms which 

 live in other regions ? The explanation is not to be 

 found in the adjustment of species to their conditions 

 of life, for under similar conditions in other regions, as 



in Australia, are found forms wholly 



Do species different. But as edentate has suc- 

 change with , , , • o .1 « 



° ceeded edentate m South America, so 

 time ? ' 



marsupial has succeeded marsupial in 

 Australia. Is the explanation in both cases to be found 

 in the supposition that the recent forms in both of these 



