In the case of hybrids, it apparently depends on their whole organisation having been disturbed by being compounded from two distinct forms; the sterility being closely allied to that which so frequently affects pure species, when exposed to new and unnatural conditions of life.
Hibridoen kasuan, antzutasuna, itxura batean, bi forma ezberdinek osatuak izanak haien organismo osoa nahasi izanaren mende dago, antzutasun hau, espezie garbiak baldintza berri eta eznaturalen pean jartzen direnean izaten dutenaren oso antzekoa delarik.