Pennaceous feather Pennaceous feather The pennaceous feather is a type of feather present in most modern birds and in some other species of maniraptoriform dinosaurs. A pennaceous feather has a stalk or quill. Its basal part, called a "calamus", is embedded in the skin. The calamus is hollow and has pith formed from the dry remains of the feather pulp, and the calamus opens below by an "inferior umbilicus" and above by a "superior umbilicus". The stalk above the calamus is a solid "rachis" having an umbilical groove on its underside. Pennaceous feathers have a rachis with "vanes" or "vaxillum " spreading
A Summer Bird-Cage A Summer Bird-Cage A Summer Bird-Cage is the 1963 debut novel by Margaret Drabble published by Weidenfeld & Nicolson. The title of the novel is taken from a quotation from the play "The White Devil" by John Webster: ‘"Tis just like a summer bird-cage in a garden: the birds that are without despair to get in, and the birds within despair and are in a consumption for fear they shall never get out." The novel centres on two characters who are sisters, Sarah and Louise. At the beginning of the story Sarah (who has recently graduated from Oxford University) has