Bronn also insists that distinct species never differ from each other in single characters, but in many parts; and he asks, how it always comes that many parts of the organisation should have been modified at the same time through variation and natural selection?
Bronnek beste hau ere azpimarratzen du, espezie ezberdinek ez dutela inoiz ezaugarri bakarrean alderik elkarren artean, atal askotan baizik; eta galdetzen du ea nola gertatzen den, aldakuntzaren eta hautespen naturalaren bidez organismoaren atal asko aldi berean beti aldatzea.