A court of equity, which in its discretion may refuse to protect private rights when the exercise of its jurisdiction would be prejudicial to the public interest, see Greathouse v. Dern, 289 U. S. 352, 359, 360, or deny relief upon performance of a condition which will safeguard the public interest and secure substantial justice to the complainant, see Harrisonville v. Dickey Clay Co., 289 U. S. 334, 338, would seem bound to stay its hand in the public interest where it reasonably appears that the private right will not suffer. It is in the public interest that federal courts of equity should exercise their discretionary power with proper regard for the rightful independence of state governments in carrying out their domestic policy. Fenner v. Boykin, 271 U. S. 240, 243, 244; Massachusetts State Grange v. Benton, 272 U. S. 525, 527; Matthews v. Rodgers, 284 U. S. 521, 525; cf. Central Kentucky Natural Gas Co. v. Railroad Commission of Kentucky, 290 U. S. 264, 273. It has long been accepted practice for the federal courts to relinquish their jurisdiction in favor of the state courts, where its exercise would involve control of or interference with the internal affairs of ,a domestic corporation of the state. See Rogers v. Guaranty Trust Co., supra, 130, 131; compare Burnrite Coal Briquette Co. v. Riggs, supra, 212, 213; Canada Malting Co. v. Paterson Steamships, Ltd., 285 U. S. 413, 419-423; Langnes v. Green, 282 U. S. 531, 541. There are stronger reasons for adopting a like practice where the exercise of jurisdiction involves an unnecessary interference by injunction with the lawful action of state officers. Matthews v. Rodgers, supra, 525.
Here, upon presentation of the application for appointment of receivers, which would involve such an interference, the district judge might appropriately have required notice of the application to be given to the state officers. It was his duty to' do so if satisfied that the delay