Keel (bird anatomy) Keel (bird anatomy) A keel or carina (plural carinae) in bird anatomy is an extension of the sternum (breastbone) which runs axially along the midline of the sternum and extends outward, perpendicular to the plane of the ribs. The keel provides an anchor to which a bird's wing muscles attach, thereby providing adequate leverage for flight. Keels do not exist on all birds; in particular, some flightless birds lack a keel structure. Historically, the presence or absence of a pronounced keel structure was used as a broad classification of birds into two orders: Carinatae (from "carina", "keel"), having a pronounced
The Anatomy of Melancholy the "Anatomy" is filled with more or less pertinent references to the works of others. A competent Latinist, Burton also included a great deal of Latin poetry in the "Anatomy", and many of his inclusions from ancient sources are left untranslated in the text. "The Anatomy of Melancholy" is an especially lengthy book, the first edition being a single quarto volume nearly 900 pages long; subsequent editions were even longer. The text is divided into three major sections plus an introduction, the whole written in Burton's sprawling style. Characteristically, the introduction includes not only an author's note (titled "Democritus Junior