But as species are more variable when domesticated or cultivated than under their natural conditions, it is not probable that such great and abrupt variations have often occurred under nature, as are known occasionally to arise under domestication.

但是，由于物种在驯化或栽培时比在自然条件下变化更大，因此在自然条件下不可能经常发生如此巨大和突然的变化， 而众所周知在驯化条件下偶尔会发生这种变化。