ONE of the queerest old rookeries in London is the little old edifice in Great Knight-Rider street, just back of St. Paul's Churchyard, with its nest of courts and its ancient quadrangle, where people go to get licenses to marry--or to have divorces granted them, or to examine or prove wills--or perhaps to have a suite entered for salvage or flotsam, or jetsam,--where David Copperfield paid a thousand pounds to receive his matriculation as a proctor. This curious old relic of Roman Catholic England, where the wills of the British nation are preserved, is known as Doctors' Commons. It is a college of civil, canon, and maritime law, and here all cases that belong to these three divisions of English law, as also divorce suits, are entered, argued, and decided. The lawyers who practice here are all well to do, snug, aristocratic old fellows, and enjoy good living and nothing to do as no other disciples of the legal profession can. It is called Doctor's Commons because the doctors or students at law used to eat in common, or dine together in a hall in the old days when the Archbishop of Canterbury acknowledged the supremacy of the See of St. Peter. In the Doctors' Commons are--the Court of Arches, named from having been formerly kept in Bow Church, Cheapside, originally built upon arches, and the Supreme Ecclesiastical Court of the Province of Canterbury--the other English Ecclesiastical Province being that of York; the Prerogative Court, where all contentions arising out of testamentary causes, are tried; the Consistory Court of the Bishop of London; and the High Court of Admiralty; all these courts hold their sittings in the college hall, the walls of which are covered with the richly-emblazoned coats of arms of all the doctors who have practiced here for two hundred years past. The Court of Arches has a jurisdiction over thirteen parishes, or "peculiars," which form a "Deanery," exempt from the authority of the Bishop of London, and attached to the Province of the Archbishop of Canterbury, who is Primate of England. This court decides, as in the days of Wolsey, in all cases of usury, simony, heresy, sacrilege, blasphemy, apostacy from Christianity, adultery, fornication, bastardy, partial and entire divorce, and many exploded offenses, which in the Nineteenth century become farcical when tried in an ecclesiastical court. Fighting or brawling in church or vestry are also offenses under the jurisdiction of this absurd old court, but they are seldom or ever brought up in these days, as the newspapers are sure to seize upon such trials as subjects for derision and satire. Still the statutes are in existence and will probably never be repealed until the Established Church of England is abolished.