Report of National Museum, 1887.— Hornaday.
Plate VIII.
| Development of the Horns of the American Bison | ||
| 1. The Calf. | 4. Spike Bull 3 years old. | 6. Bull, 11 years old. |
| 2. The Yearling. | 5. Bull, 4 years old. | 7. Old "stub-horn" Bull, 20 years old. |
| 3. Spike Bull 2 years old. | ||
