However, the latter theory lacks clear credibility because, depending the material, the way of counting the number of human holes is different, including the theory that it includes the urinary hole, saving the navel.
しかし、穴の数え方が資料によってまちまちのため（例えば、へそではなく尿口を数えるなど）の説もあり、信憑性は今ひとつである。