Nor can the increased number of births in the colony be neglected in accounting for the growth of population. The historian Bruce, referring to the period from 1634 to 1649, in which the population trebled, says: "The faster growth during this interval was due, not to any increase in the number of new settlers seeking homes in Virginia, but rather to the advance in the birth-rate among the inhabitants. There was by the middle of the century a large native population thoroughly seasoned to all the trying variations of the climate and inured to every side of plantation life, however harsh and severe it might be in the struggle to press the frontier further and further outward."[28] It may then be asserted positively that the growth of population between the dates 1649 and 1670 was not due to an influx of Cavaliers. Had many men of note fled to Virginia at this period their arrival would scarcely have escaped being recorded. Their prominence and the circumstances of their coming to the colony would have insured for them a place in the writings of the day. A careful collection of the names of those Cavaliers that were prominent enough to find a place in the records, shows that their number was insignificant. The following list includes nearly all of any note whatsoever: Sir Thomas Lunsford, Col. Hammond, Sir Philip Honeywood, Col. Norwood, Stevens, Brodnax, Welsford, Molesworth, Col. Moryson, John Woodward, Robert Jones, Nicholas Dunn, Anthony Langston, Bishop, Culpeper, Peter Jenings, John Washington, Lawrence Washington, Sir Dudley Wiat, Major Fox, Dr. Jeremiah Harrison, Sir Gray Shipworth, Sir Henry Chiskeley and Col. Joseph Bridger. Of this number a large part returned to England and others failed to establish families in the colony. How few were their numbers is shown by the assertions of colonial writers. Sir William Berkeley reported in 1671 that Cromwell's "tyranny" had sent divers worthy men to the colony. Hugh Jones, writing in 1722, speaks of the civil wars in England as causing several families of good birth and fortune to settle in Virginia. This language certainly gives no indication of a wholesale immigration of Cavaliers.