Thus, as I believe, we can understand why, with domesticated animals, varieties have not been produced which are mutually sterile; and why with plants only a few such cases, immediately to be given, have been observed.
Horrela, ulertu ahal dugu, nik uste, zergatik ez den sortu etxe-animalien artean elkarrekiko antzu den aldakirik, eta zergatik ez diren hauteman landareetan horrelako kasu banaka batzuk besterik, berehala aipatuko ditugunak.