These actions are brought to recover the amount of a tax due to the Commonwealth under St. 1864, c. 208. It was necessary for the plaintiff to state in his declaration such substantive facts as would, if proved, entitle him to recover. If he neglected to do this, the defendants might for some defects answer in abatement, and for others they might demur to the declaration, on the ground that it did not set forth a legal cause of action, stating the particulars in which the defect consisted. Gen. Sts. c. 129, §§ 11,12. Or the court might, either *285on motion of the defendants or on its own motion, order the plaintiff to file a statement of such further particulars as might be necessary for the further information of the defendants or the court. § 58.

But a defendant is not bound to demur to a declaration, or to ask for a further statement of particulars, and if he files an answer and goes to trial the court will not set aside a verdict against him on account of any defects in the declaration. In the report of the commissioners who framed our system of pleading and practice, they say: “ Allegations are made that the parties may have notice; but if both parties were content to act upon what they had, why should either be allowed to complain afterwards ? ”

In the first of these cases, the defendants merely filed an answer in which they made no denials, but averred certain substantive facts in defence. Upon these pleadings the parties went to trial before a jury. As the plaintiff’s allegations had not been denied, the court and jury were to regard them as admitted to be true. The plaintiff relied on them, and offered no further evidence. If these allegations were sufficient to maintain the action, the plaintiff was entitled to a verdict, unless the defendants should establish a defence. The defendants offered no evidence, but objected that the facts stated in the declaration and not denied were insufficient to maintain the action. This state of the case made it necessary for the court to instruct the jury on that subject. The declaration did not state that the defendants were a mining company, or that the plaintiff was authorized by law to bring the action in his own name, and therefore neither of these facts appeared. But both were necessary to maintain the action. The statute, of which the court must take judicial notice, requires that the action shall be brought in the name of the Commonwealth, and it was mining companies that were made subject to the tax. The jury ought therefore to have been ) nstructed to find a verdict for the defendants, and the instruction to find a verdict for the plaintiff was erroneous.

In the second case, the defendants filed an answer merely *286denying that they owed the plaintiff the sum stated in his. declaration. This is merely a denial of a legal conclusion, and is equivalent to the general issue, which the practice act abolished. Granger v. Ilsley, 2 Gray, 521. Van Buren v. Swan, 4 Allen, 380. But the plaintiff did not demur to the answer, nor file any motion in respect to it, and the court suffered the cause to go to tidal without making any order as to the answer. After verdict, it is to be assumed that both the court and the parties were sufficiently informed of the nature of the case to be tried. The parties went to trial upon the allegations in the declaration which, not being denied, were admitted to be true, and no evidence was offered. In these cases the jury should have been instructed that the facts alleged and admitted did not show that the plaintiff was authorized to maintain the action for the tax in his own name, and the instructions given were erroneous. The plaintiff contends that he was entitled to a verdict as upon nil dieit, but no such question is open here; the exceptions presented to us relate merely to the instructions given to the jury.

The case of Gray v. Paxton, reported in Quincy, 541, is quite in point. That was an action brought by the treasurer of the Province of Massachusetts Bay to recover a tax assessed by the Province. The defendant set up, by a plea in abatement, the same defence that is made so inartificially in these cases, namely, that the action should be in the name of the Province, and not in the name of the treasurer. The plea was overruled in the inferior court, but upon appeal to the superior court it was sustained, and at August term 1761 judgment was entered that the writ abate.

The third case comes before us upon an agreed statement of facts, in which there is nothing stated to aid the declaration. Upon the defects of the declaration, therefore, the defendants are entitled to judgment; for the declaration refers to the tax act, and thus shows that the action should have been brought in the name of the Commonwealth, and not in the name of the treasurer.

Exceptions sustained in the first and second cases. Judgment for the defendants in the third ease.