Note {248} — Chapter II · ON THE VARIATION OF ORGANIC BEINGS IN A WILD STATE; ON THE NATURAL MEANS OF SELECTION; AND ON THE COMPARISON OF DOMESTIC RACES AND TRUE SPECIES
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«Note in original.» Animals seem more often made sterile by being taken out of their native condition than plants, and so are more sterile when crossed.
We have one broad fact that sterility in hybrids is not closely related to external difference, and these are what man alone gets by selection.