Finally, then, although we are as ignorant of the precise cause of the sterility of first crosses and of hybrids as we are why animals and plants removed from their natural conditions become sterile, yet the facts given in this chapter do not seem to me opposed to the belief that species aboriginally existed as varieties.
Azkenean, bada, lehen gurutzaketen eta hibridoen antzutasunaren kausa zehatzari buruz eta beren baldintza naturaletatik ateratzen diren animalia eta landareen antzutasunaren zergatiari buruz era berean ezjakinak garen arren, kapitulu honetan emaniko egitateei ez deritzet espezieak jatorriz aldaki gisa existitu zirela dioen eritziaren kontrako.