number of toes is a property of bone structure
bone is bone_structure. humans has five_toes_on_each_foot we has five_toes_on_each_foot we has not five_toes_on_each_foot toe is anatomical_structure. each has ten_fingers_and_ten_toes foot has five_toes eye_socket is bone_structure. we has toes we has ten_toes_on_feet