1 centre for the shaft of the tibia in the seventh week (i.u.l.).

1 centre for the shaft of the fibula in the eighth week (i.u.l.).

1 centre for the upper end of the tibia in the first year-union at twenty.

1 centre for the upper end of the fibula in the fourth year —union at twenty-five.

1 centre for the lower end of the tibia in the second year —union at eighteen.

1 centre for the lower end of the fibula in the second year—union at twenty. The tarsus :

The os calcis, astragalus and cuboid alone have centres of ossification at birth, these appearing respectively in the sixth, seventh, and ninth months. The os calcis possesses a secondary centre, appearing about the tenth year, for its posterior surface. The metatarsus and phalanges :

Centres appear as in metacarpus, etc.