It shall be lawful for the Court of Session or Court of Exchequer, as the case may be, to limit upon cause shown the caution to be found by factors F1guardiansand tutors and curators to a specified amount, and also to authorize, if they shall deem it expedient, bonds or policies of the British Guarantee Association, or other public company incorporated by Act of Parliament or royal charter carrying on guarantee business within Scotland, to be accepted and taken instead of bonds of caution by private individuals.