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
Names for the human species "animal capable of rationality", a term used in medieval scholasticism (with reference to Aristotle), and also used by e.g. Carl von Linné 1760, Immanuel Kant 1798. Based on the same pattern is "animal sociale" or "social animal" "animal laborans" "laboring animal" (Hannah Arendt 1958) and "animal symbolicum" "symbolizing animal" (Ernst Cassirer 1944). The binomial name "Homo sapiens" was coined by Carl Linnaeus (1758). Names for other human species were introduced beginning in the second half of the 19th century ("Homo neanderthalensis" 1864, "Homo erectus" 1892). There is no consensus on the taxonomic delineation between human species, human subspecies and the