These cases were tried together in the lower court. The defendants appeal form a directed verdict and judgment thereon for the plaintiff based on a motion for directed verdict by the plaintiff at the close of the plaintiff's evidence, without affording the defendants any opportunity to offer evidence. "A motion for a directed verdict may be made at the close of the evidence offered by an opponent or at the close of the case." Rule 50 (a); CPA 50 (a) (Code Ann. 81A-150 (a)). Under this rule the defendant, but not the plaintiff, may move for a directed verdict at the close of the evidence for the plaintiff. The trial judge had no authority to direct a verdict for the plaintiff on motion of the plaintiff at this stage of the trial.