*174 Mr.' Justice Peckham,

after stating the facts, delivered the opinion of the court.

An answer to the third question, “'Had the Circuit Court the legal right or power to order a surgical examination of the plaintiff,” will be all that is necessary for the action of the court below.

It is settled in this court that no power to make such an order exists at common law ; in other words, the court has no inherent power to make it. Union Pacific Railway v. Botsford, 141 U. S. 250. In that case there was no statute of the State in which the United States court was held which authorized the order. There is no intimation in the opinion that a statute of a State directly authorizing such examination would be a violation of the Federal Constitution, or invalid for any other reason.

In this case we have such a statute, and by section 721 of the Eevised Statutes of the United States it is provided that “ the laws of the several States, except where the Constitution, treaties or statutes of the United States otherwise require or provide, shall be regarded as rules of decision in trials at common law in courts of the United States, in cases in which they apply.”

Does not this statute of the State apply in trials at common law in the United States .courts sitting in the State where the statute exists ?

The case before'us is a common law action; it is one to recover damages for a tort, which is an action of that nature. It was being tried in the State which enacted the statute, and the court was asked to apply such statute to the trial of an action at common law.

Neither the Constitution, treaties nor statutes of the United States otherwise require or provide. The statute concerns the evidence which may be given on a trial in New Jersey, and it does .not conflict with any statute of the United States upon that subject. It is not a question of a general nature, like the law merchant,' but simply one concerning evidence based upon a local statute applicable to actions brought within the State to recover damages for injury to the person. The Statute comes *175 within the principle of the decisions of this court holding a law of the State of such a nature binding upon Federal courts sitting within the State. Swift v. Tyson, 16 Pet. 1, 18; Nichols v. Levy, 5 Wall. 433; Watson v. Tarpley, 18 How. 517, 520; Ex parte Fisk, 113 U. S. 713.

It was held in United States v. Reid, 12 How. 361, that the provision of the law of Congress did not extend to criminal offences against the United States, for that would be to give to the States* the power of prescribing the rules of evidence in trials for. offences against the United States. It was said, however, that the section was intended to confer upon the courts of the United States the jurisdiction necessary.to enable them to administer the laws of the States.

We are not aware of any reason why this law of the State does not apply to courts of the United States under the section of the Kevised Statutes above quoted. There is no claim made that the statute violates the Federal Constitution, and we are of opinion that such a claim would have no foundation, if made.

Counsél for the plaintiff refers in his argument to the opinion in the Botsford case, where it is stated (at page 256) that the question is one which is not governed by the law or practice of the State in which the trial is. had, but that* it depends upon the power of the national courts under the Constitution and laws of the United States, and he argues therefrom that the state statute is immaterial, and can furnish no foundation for the exercise of the power by the Federal court. We do not dispute that if there were no law of the United States which, in connection with the state law, could be referred to as in effect providing for the exercise of the power, the court could not grant the order under the decision in the case of Botsford. But we say there is a law of the United States which does apply the laws of the State where the United States court sits, and where the State has a law which provides for the making of an order for the examination of the person of a plaintiff in a case like this, the law of the United States applies that law to cases of such a nature on trial in Federal courts sitting in that State. In the Botsford case there was.no state law, and consequently no found* ationfor the application of the law of the United States.

*176 In Ex parte Fisk, 113 U. S. 713, the statute of the State of New York, in relation to the examination of parties before trial, was held to be in conflict with the act of Congress providing for the examination of witnesses in courts of the United States, and was, therefore, inapplicable in those courts ; but the statute in this case is not in conflict with any statute of the United States. It does not conflict with section 861 of the Revised Statutes, providing for the oral examination of witnesses in open court. On the contrary, whatever information may be obtained by the surgeon who examines the plaintiff under the statute in question can be availed of only by the defendant’s producing the witness and examining him in open court, or by deposition, if he come within the exception mentioned in section 863 and the following sections.

The validity of this statute has been affirmed by the Supreme Court of New Jersey in McGovern v. Hope, 42 Atl. Rep. 830; to appear in 63 N. J. Law. The opinion of the court was delivered by Mr. Justice Depue and the court held that the act was within the power of the legislature, and was not an infringement upon the constitutional rights of the party.

The validity of a statute of this nature has also been upheld in Lyon v. Manhattan Railway Company, 142 N. Y. 298, although the particular form of that statute would probably be regarded as conflicting with the law of Congress in relation to the examination of a party as a witness before trial, and hence might not. be enforced in courts of the Ünited States sitting within the State of New York, but the validity of a statute providing for the examination of the person of a plaintiff in an action to recover for injuries is upheld and declared not to be in violation of the constitutional rights of the party.

The citizenship of the plaintiff at the time of the injury is not material so long as the court below has jurisdiction of the case and the parties at the time of the commencement of the action.

In those States in which it has been held that the court has inherent power to order the examination of a plaintiff in this class of action without the aid of a statute, all has been said that could be urged in favor of such power on grounds connected with public policy and the .due and proper administration of *177 justice by tbe courts. This court has taken another view of the subject, in the decision of Botsford’s case, above cited. But by reason of the statute of New Jersey, in which State this action was brought, there being no law of Congress in conflict therewith, we hold that the courts of the United States therein sitting have the power under the statute and by virtue.of section 721 of the Revised Statutes of the United States to order the examination of the person of the plaintiff, and we, therefore, answer the third question of the court below in the affirmative, and

It will be áo certified.

Mr. Justice Harlan dissented.