But if the count of the second 10 is made on the toes in place of the fingers, the element of repetition which entered into the previous method is now wanting.

Instead of referring each new number to the 10 already completed, the savage is still feeling his way along, designating his new terms by such phrases as "1 on the foot," "2 on the other foot," etc.

And now, when 20 is reached, a single series is finished instead of a double series as before; and the result is expressed in one of the many methods already noticed--"one man," "hands and feet," "the feet finished," "all the fingers of hands and feet," or some equivalent formula.

Ten is no longer the natural base.

The number from which the new start is made is 20, and the resulting scale is inevitably vigesimal.