Illustration of the three-compartment stomach of a llama. The first compartment (C1) is the fermentation vat. Note the ventral saccules, which have a glandular epithelium. The second compartment (C2) seems to function similar to the reticulum of ruminants. The third compartment (C3) has both fermentative and acid-secreting regions, with the aborad portion functioning as a true stomach analogous to the abomasum. Illustration by Dr. Gheorghe Constantinescu. Adapted, with permission, from the Color Atlas of Large Animal Applied Anatomy by Hilary M. Clayton and Peter F. Flood, Mosby-Wolfe, 1996.