As the accumulation of each formation has often been interrupted, and as long blank intervals have intervened between successive formations, we ought not to expect to find, as I attempted to show in the last chapter, in any one or in any two formations, all the intermediate varieties between the species which appeared at the commencement and close of these periods:
Formazio bakoitzaren metaketak sarri etenaldiak izan dituenez, eta jarraikako formazioen artean hutsarte luzeak izan direnez gero, ez dugu espero izan behar formazio bat edo bitan aurkitzerik, aurreko kapituluan frogatzen saiatu naizen moduan, aldi hauen hasieran eta amaieran agertu ziren espezieen bitarteko aldaki guztiak;