The shaft of the tibia ossifies from one centre, the distal end from a second, and the proximal end from two more.
Fig. 80. A, right manus, B, right pes of a Dog
(Canis familiaris) × ½ (after von Zittel).
| 1. bone representing the fused | 9. fifth metacarpal. |
| scaphoid, lunar and | 10. astragalus. |
| centrale. | 11. calcaneum. |
| 2. cuneiform. | 12. navicular. |
| 3. trapezium. | 13. middle cuneiform. |
| 4. trapezoid. | 14. external cuneiform. |
| 5. magnum. | 15. cuboid. |
| 6. unciform. | 16. first metatarsal. |
| 7. pisiform. | The digits are numbered with |
| 8. first metacarpal. | Roman numerals. |
The fibula (fig. 79, C) is a distinct but very slender bone, somewhat expanded at both ends. It lies external to the tibia and articulates by its proximal end with the head of the tibia, and by its distal end with the calcaneum. Its shaft and proximal end ossify from one centre, and its distal end from a second.
The Pes.
The structure of the pes corresponds closely with that of the manus. It is divided into:—
a. The tarsus or ankle formed of a group of small bones.
b. The foot, which includes, firstly, some elongated bones, the metatarsals, forming what corresponds to the sole of the foot, and secondly the phalanges, which form the toes.