The Alimentary Canal of a Fowl
Birds usually have three cavities or stomachs. Labels: 1, The esophagus. 2, Ingluvies (crop). 2, Proventriculus (secreting stomach). 4. Triturating stomach (gizzard). 5, Intestine. 6, Two caeca.
Cutter, Calvin First Book on Analytic Anatomy, Physiology and Hygiene, Human and Comparative (Philadelphia: J. B. Lippincott & Co., 1875) 70