The inability of the martlet to land is often seen to symbolize the constant quest for knowledge and learning, as in the arms of McGill University and the University of Victoria (where the student newspaper is called The Martlet). It has been suggested that this same restlessness is the reason for the use of the martlet in English heraldry as the cadency mark of the fourth son: the first son inherited the estate, the second and third traditionally went into the Church and the Army, and the fourth had no well-defined place.
Centuries after his death, Edward the Confessor was assigned a coat of arms containing five golden martlets; Richard II of England combined this coat with the Plantagenet arms, and it later became the basis of the arms of Westminster Abbey and Westminster School.
The arms of the Valence earls of Pembroke were orled (bordered) with martlets, and subsequently these are also found in the arms of Pembroke College, Cambridge.
The shield of the county of Sussex, England contains six martlets, said to represent the six traditional rapes (administrative sub-divisions) of the county.
A Complete Guide to Heraldry, Arthur Charles Fox Davies. Kessinger Publishing, 2004. ISBN 1417906308