With respect to the assumed inutility of various parts and organs, it is hardly necessary to observe that even in the higher and best-known animals many structures exist, which are so highly developed that no one doubts that they are of importance, yet their use has not been, or has only recently been, ascertained.
Zenbait atal eta organoren ustezko alferrekotasunari dagokionez, ia ez da ohartarazi behar ezagunen ditugun goi-animaliek ere hain egitura garatuak dituztenez gero, inork ez duela zalantzatan jartzen garrantzizkoak direnik, baina, hala ere, haien emendio edo zertarakoa ez da oraindik edo oraintsu arte egiaztatu.