Opinion of the Court. 234 U.S. ing the defendants as trustees complainants in said suit. The present bill then proceeds to attack the proceedings and adjudication in bankruptcy, and the title of the defendants as trustees, as fraudulent and void upon various grounds, which may be summarized as follows: That the Port Tampa Company's principal place of business was not in Massachusetts, as alleged in the petition, and that it had no business except in Florida; that it was not insolvent, and did not commit the act of bankruptcy alleged, or any act of bankruptcy; that the petitioning creditors were directors of the company and knew the company was solvent and had committed no act of bankruptcy; that the jurisdictional facts were falsely and fraudulently averred, being fabricated for the purpose of pretending to state a cause within the jurisdiction of the court; that the petitioning creditors controlled both sides of the litigation through their ownership of a majority of the company's stock; that Robinson, who entered the appearance in behalf of the Port Tampa Company, was not in fact authorized to appear for or represent the company; and that the petition was fraudulently made to appear as an involuntary petition by creditors, whereas in truth and in legal effect it was a voluntary petition on the part of the company and its officers and directors. It is also alleged that the appointment of defendants as trustees in the place of Burr on March 12, 1909, was invalid, because no judge or referee appointed them, their claim being that in fact they were appointed trustees at a meeting of creditors, whereas complainants allege that the pretended call by the referee for the meeting of creditors was issued at a time when there was no vacancy in the office of trustee; that ten days' notice of the meeting was not given by mail to all the creditors as required by law; that the only creditor who attended the meeting was one Wills, a director of the company, and that there were ten other creditors who had proven claims; that Wills did not own a bona fide provable claim to the amount of onehalf of the claims that had been proven; and that the appointment of defendants as trustees was made by Wills alone. Complainants insist that there was no power or jurisdiction in any creditor or creditors to appoint defendants as trustees on March 12, 1909, because at that time there was no vacancy in the office of trustee, since Burr had not then resigned and his resignation had not been accepted by the court. The bill further avers that in their answer to the supplemental bill in the equity suit in the circuit court of Polk County, Florida, the present complainants set up the defense of "want of jurisdiction of the said court of bankruptcy to render any decree of adjudication, and that such alleged decree was void on the face of the said proceedings"; that this part of the answer was excepted to and the exceptions sustained by the order of the Polk County circuit court; that on appeal, the Florida Supreme Court affirmed this order on July 3, 1912, ruling that all such defenses were collateral attacks upon the bankruptcy proceedings, which were not permissible, the ruling being expressed in the following words: "The assaults made upon the bankruptcy proceedings in the Federal Court of Massachusetts by the answer of the appellants to the supplemental bill of the appellees in the particulars wherein said answer was excepted to by the appellees is simply a collateral attack upon the judgments, orders and proceedings in said bankruptcy court that is not permissible either by way of defence to the supplemental bill or to the original bill as amended;" that by reason of the said judgment of the Florida courts the present complainants cannot by way of defense to the bills of complaint in those courts "have and obtain that speedy, adequate and appropriate relief that this court is competent to render upon this original bill of complaint; and your orators fear that the Florida courts will decline to adjudicate as to the character Opinion of the Court. 234 U.S. and title of the defendants as trustees and their competency to attack your orators' title to said properties, as herein set forth, upon any answer to the said bills in the said state court." The present amended bill further sets up that "Upon the facts hereinbefore set forth, which are conclusively provable to be true by the record of the proceedings of the said court of bankruptcy, if the said Port Tampa Company had any title to any of the aforesaid properties, legal or equitable, at the time of the said alleged decree of adjudication, such title still remains in the said company; that your orators are still liable to be sued by the said company in any court of competent jurisdiction to assert such title, and that a final decree in the Florida state court for or against the defendants as such alleged trustees would not be pleadable in bar of a suit by the said company against your orators to assert such title." The specific prayer is for a decree to restrain defendants "from asserting or claiming as trustees in bankruptcy, in any court or place, any right, title or interest in or to any of the properties herein described until the further decree of this court." There is also a prayer for general relief. Appended as exhibits and made a part of the bill are the copies of the petition, subpoena, return, and appearance in the bankruptcy proceedings, already mentioned, and a transcript of the record of the ejectment suit in the United States Circuit Court for the Southern District of Florida. The District Court, in sustaining the demurrer, held that since upon the face of the bankruptcy proceedings there was no want of jurisdiction over the parties or the subject-matter, and the decree was not void in form, it could not be collaterally attacked, and could be assailed only by a direct proceeding in a competent court; citing Lamp Chimney Co. v. Brass & Copper Co., 91 U. S. 656, 662; Graham v. Boston, Hartford & Erie R. R. Co., 118 U. S. 161, 178. Treating the present suit as a direct at tack, the court held, first, that no right or interest of complainants appeared to be so prejudiced by the adjudication in bankruptcy as to entitle them to equitable relief against it; that the adjudication concerned only the bankrupt and its creditors, since it made no difference to complainants whether the claim to the Florida properties was asserted by the bankrupt itself or by its trustees; that the allegation that a final decree in the Florida suit would not bar an action brought by the company itself was a mere conclusion of law, not admitted by the demurrer, and an unsound conclusion in view of the facts alleged; that, the adjudication not having been questioned by the bankrupt or its creditors, they were bound by it, and by virtue of it the trustees were in the bankrupt's place so far as concerned any claim that it could assert to the Florida properties. And, secondly, that there was a defect of necessary parties, because the only defendants named in the bill were the bankruptcy trustees, respecting whom it was not alleged that they were parties to the bankruptcy proceedings, nor that they participated in the fraud whereby the adjudication was alleged to have been procured. The Circuit Court of Appeals, while agreeing with this reasoning, placed its decision upon the ground that complainants were invoking not the powers of the District Court in bankruptcy, but its general powers as a court in equity; that it also appeared that the proceedings in Florida were insituted by a bill in equity with the parties reversed; that the Florida court was a chancery court and a court of superior jurisdiction in equity, and for present purposes of equal dignity and authority with the District Court of the United States for the District of Massachusetts; that the bill in substance merely invoked the general equitable jurisdiction of the District Court in order to restrain proceedings in a state court proceeding in equity in a prior suit between the same parties; and that this ran counter to § 720, Rev. Stat. (§ 265, Jud. Code, 36 Stat. 1162, c. 231), as well as to the general principle that the authority of the court first acquiring jurisdiction, the parties being the same, must prevail; citing Marshall v. Holmes, 141 U. S. 589, 596; and Central National Bank v. Stevens, 169 U. S. 432, 462. There is a motion to dismiss the appeal, based upon the ground that the jurisdiction of the District Court depended solely upon diversity of citizenship, and that therefore the decree of the Circuit Court of Appeals is final, under § 128, Judicial Code (36 Stat. 1133, c. 231). The motion must be granted unless the suit was one arising under the laws of the United States, within the meaning of the first subdivision of § 24 of the Code. The rule is firmly established that a suit does not so arise unless it really and substantially involves a dispute or controversy respecting the validity, construction, or effect of some law of the United States, upon the determination of which the result depends. And this must appear not by mere inference, but by distinct averments according to the rules of good pleading; not that matters of law must be pleaded as such, but that the essential facts averred must show, not as a matter of mere inference or argument, but clearly and distinctly, that the suit arises under some Federal law. Hanford v. Davies, 163 U. S. 273, 279; Mountain View Mining & Milling Co. v. McFadden, 180 U. S. 533, 535; Defiance Water Co. v. Defiance, 191 U. S. 184, 191; Arbuckle v. Blackburn, 191 U. S. 405, 413; Bankers Casualty Co. v. Minneapolis &c. Ry. Co., 192 U. S. 371, 383; Shulthis v. McDougal, 225 U. S. 561, 569. We have not considered whether the action could be regarded as ancillary to the proceedings in bankruptcy, and for that reason maintainable in the District Court as a suit arising under the laws of the United States (see Freeman v. Howe, 24 How. 450, 460; Minnesota Co. v. St. Paul Co., 2 Wall. 609, 633; Buck v. Colbath, 3 Wall. 334, |