Digestion a thin-walled expanded portion of the alimentary tract used for the storage of food prior to digestion. In some birds it is an expanded, muscular pouch near the gullet or throat. In adult doves and pigeons, the crop can produce crop milk to feed newly hatched birds. Certain insects may have a crop or enlarged esophagus. Herbivores have evolved cecums (or an abomasum in the case of ruminants). Ruminants have a fore-stomach with four chambers. These are the rumen, reticulum, omasum, and abomasum. In the first two chambers, the rumen and the reticulum, the food is mixed with saliva and
Pouch (marsupial) Pouch (marsupial) The pouch is a distinguishing feature of female marsupials and monotremes (and rarely in the males as in the water opossum and the extinct thylacine); the name marsupial is derived from the Latin "marsupium", meaning "pouch". Marsupials give birth to a live but relatively undeveloped fetus called a joey. When the joey is born it crawls from inside the mother to the pouch. The pouch is a fold of skin with a single opening that covers the nipples. Inside the pouch, the blind offspring attaches itself to one of the mother’s nipples and remains attached for as long