The plaintiff may insert in the writ a direction to the garnishee, except if he is described as an executor, administrator or trustee in insolvency, in which case he shall not be so cited in, to appear before the court to which the process is returnable and there disclose on oath whether he has in his hands the goods or effects of the defendant, or is indebted to him; and, at any time during the pendency of a foreign attachment suit, any garnishee who might have been so cited in but was not may be cited by the court to appear before it, at a time appointed, to make such disclosure.