Mivart then asks how did natural selection remove in the adult kangaroo (and in most other mammals, on the assumption that they are descended from a marsupial form), "this at least perfectly innocent and harmless structure?" It may be suggested in answer that the voice, which is certainly of high importance to many animals, could hardly have been used with full force as long as the larynx entered the nasal passage;
Mivartek orduan galdetzen du: nola kendu zion hautespen naturalak kanguru haziari (eta ugaztun gehienei, forma martsupial batetik etorriak direla onartuz gero) "egitura behinik behin erabat errugabe eta kaltegabe hau?".