if we make the same allowances as before for our ignorance, and remember that some forms of life have changed very slowly, enormous periods of time having been thus granted for their migration, the difficulties are far from insuperable;
Gure teoriaren arabera guraso-sorburu bakarretik hedabanatu diren genero bereko espezie bereziei dagokienez, kontuan hartzen badugu lehen bezala gure ezjakintasuna, eta gogoan badugu forma organiko batzuk oso astiro aldatu direla-hain astiro ezen denbora tarte izugarriak eman behar baitzaizkie beraien emigrazioetarako-, ez dago zailtasun gaindiezinik, ezta gutxiagorik ere;