Comparison of the Molar Teeth of a Human, Horse, and Dog
The molar teeth of a human, horse and dog. The first image to the left in a molar tooth of a horse. Labels: 1, The enamel. 2, The ivory. 3, Canals for blood vessels. The center image is a molar tooth of a human. Label: 1, The enamel. 2, The ivory. 3, The cavity containing blood vessels. 4, 5, Artery and nerve. The image on the right is a molar tooth of a dog. Labels: 1, The enamel. 2, The ivory. 3, Cavity for blood-vessels.
Cutter, Calvin First Book on Analytic Anatomy, Physiology and Hygiene, Human and Comparative (Philadelphia: J. B. Lippincott & Co., 1875) 68