But how to obtain the beginning of such useful development?" In answer, it may be asked, why should not the early progenitors of the whales with baleen have possessed a mouth constructed something like the lamellated beak of a duck?
Baina nola lortu garapen baliagarri honen hasiera?". Honi erantzunez, galde daiteke, bizardun baleen lehen arbasoek zergatik ez zuten izanen ahoa ahatearen xaflatxodun mokoa bezala eraikia?