So, naturalists observe, a flea; Hath smaller fleas that on him prey; And these have smaller fleas to bite 'em, And so proceed ad infinitum. — Jonathan Swift Copy Share Image
Now when naturalists observe a close agreement in numerous small details of habits, tastes and dispositions between two or more domestic races, or between nearly-allied natural forms, they use this fact as an argument that all are descended from a… — Charles Darwin Copy Share Image
