“A contract may be illegal either by the common law or under a statute; in the latter case it is highly desirable to cite the statutory provision. That will give the plaintiff notice of the case to be met, and he will prepare himself with all the evidence and arguments that may bear on illegality. Then both sides will be able to present their evidence and arguments of law in full, and the trial Court will have all the circumstances and be able to adjudicate on the issue of illegality. That is made clear in the judgment of Lord Moulton in the House of Lords case at p. 476, where his Lordship said this:- “The plaintiffs have received no notice that the point will be raised, and are presumably not prepared with the necessary evidence. Even if they are in a position to call the evidence they are not at liberty to do so, because they are only entitled to call evidence on the issues raised by the pleadings. The facts before the Court at the end of the case are therefore only a casual selection from the surrounding circumstances, and the Court has no longer the right to treat them as properly and fully representing those surrounding circumstances so as to Justify its pronouncing on their true effect upon the contract.”