Q. What do you mean by Periodical?
A periodical is a publication appearing at regular intervals. Each issue is called a number and collectively these numbers comprise a volume. Sponsors of periodicals often publish more than one serial. A society may publish a monthly serial to provide a source of publication for a variety of relatively short papers contributed by its members, together with records of its own proceedings. Such a periodical is usually entitled Journal, Annal, Bulletin or Proceeding. Botanists generally use the abbreviated form of the titles in citations and bibliographies and for this reason it is necessary to know the full title as catalogued. Libraries widely differ in the method of cataloguing titles of periodicals and too often fail to cross index titles under the various possible headings, In general if a periodical is published by a government or municipal institution it is catalogued under the name of the sponsoring country or city; likewise if by a society, academy or educational institution it is catalogued under the title of the organisation which is in turn placed under the name of the city where it has its seat.