Mo. Rev. Stat. § 491.360: Continuance of case — associate circuit judge to notify witnesses.

When any cause shall be continued by the associate circuit judge, it shall be his duty forthwith to call before him all witnesses summoned in the cause, and verbally notify such as may attend to appear before him, to testify in the cause, on the day set for trial, which verbal notice shall be in all respects as valid as a summons; and the associate circuit judge shall enter in his record the fact of notice and the names of the witnesses notified. No summons shall thereafter issue to any witness notified as directed.