Under the old practice of the English court of probate, was a notice given by a registrar of the principal registry to a person who had entered a caveat, warning him, within six days after service, to enter an appearance to the caveat in the princinpal registry, and to set forth his interest concluding with a notice that in default of his doing so the court would proceed to do all such acts, matters, and things as should be necessary. By the rules under the judicature acts, a writ of summons has been substituted for a warning. Sweet