Opinion of the Court. 339 U.S. Y plus 1 is to accord them service different from that given other shippers under Ex parte 104 and supplemental proceedings. By the orders in the instant cases, line-haul is translated, as it were, into the tariffs as beginning and ending where the Commission fixed it and not where the appellee-carriers fixed it by tariff. Thereafter, the charge for line-haul must be to the interchange tracks and not to the point fixed in the tariff. Transportation to the latter point at the line-haul rate would be preferential and would violate § 6 (7). The tariff which is considered by appellee-carriers as applicable only to the Leadville plant is set forth in the margin. It may be noted that this tariff does not provide, as does the 1938 tariff applicable to the other plants, that the line-haul rate includes the intraplant services. Further, the "movement" specified in delivery of a linehaul shipment includes not just one, as provided by the 1938 tariff, but several switching operations which the Commission has classified as "interrupted" terminal switching services, performed for the convenience of the industry only. The Commission has fixed the point at which linehaul or transportation service ends as the "flat yard" at Leadville and finds there are services performed beyond this point. These industry services must be so com 7 This tariff is almost identical with that which was applicable to all of the plants in 1920. The smelters, we are informed, pay the 1938 tariff under protest, and insist upon the 1920 tariff. "DELIVERY OF LINE-HAUL CARLOAD SHIPMENT DESTINED TO SMELTER AT LEADVILLE, COLO. "Delivery of a line-haul carload shipment destined to smelter at Leadville, Colo., will include movement within smelter plant over track scales, to and from thaw-house, to and from a smelter sampler or to and from a combination sampler and concentrator to a designated unloading point indicated by the sampling company." 186 Opinion of the Court. pensated for, and may not be wrapped up in delivery of a line-haul shipment. "Since the Commission finds that the carriers' service of transportation is complete upon delivery to the industries' interchange tracks, and that spotting within the plants is not included in the service for which the line-haul rates were fixed, there is power to enjoin the performance of that additional service or the making of an allowance to the industry which performs it." United States v. American Sheet & Tin Plate Co., 301 U. S. 402, 408. Obviously the plant services at Leadville are different from those at Midvale, Garfield, and Murray under the 1938 tariff, which only emphasizes the wisdom of Congress in empowering the Commission to fix the point where line-haul begins and ends with a view to giving all shippers equivalent service. The Commission has standardized such service as team track or simple placement switching. What we now hold is that the Commission has the power to fix the point at which line-haul or carrier service begins and ends. This is necessary because the need for switching varies from plant to plant; indeed, some plants may need no intraplant switching service. Thus, unless the Commission can fix the beginning and ending point of the line-haul, some shippers would pay an identical line-haul rate for less service than that required by other industrial plants. See Baltimore & Ohio R. Co. v. United States, 305 U. S. 507, 526. A different point fixed by the carrier in its tariff gives service in excess of that accorded shippers generally as established in Ex parte 104, and therefore amounts to an unlawful preferential service. As to the argument that to require the carriers to conform to the Commission's orders would require the appellee-smelters to pay twice for their service, the short Opinion of the Court. 339 U.S. answer is that appellees misconceive the scope of this proceeding, which is solely to define what is embraced in line-haul transportation. We accept the admonition of the Commission in its second report, quoted supra, and reiterated in its brief, that it was not here concerned, and made no finding, as to whether the charge made for the service was or was not compensatory. We think that the Commission has authority to exclude rate questions from this proceeding. If the carriers so wish, they may file a new tariff to conform their charges to the services indicated in the Commission's order. 49 U. S. C. § 6 (1) and (3). If the carrier makes a double or unreasonable charge, the industry may be heard upon the reasonableness of the rate. 49 U. S. C. §§ 9, 13, 15. Finally it is contended that the District Court judgment should be affirmed because there was no appeal from the judgment and mandate when the case was sent back to the Commission, the court having found that there was no evidence to sustain a Commission finding that the line-haul rates were not compensatory for the services rendered. Appellees argue that that decision became the law of the case. The rule of the law of the case is a rule of practice, based upon sound policy that when an issue is once litigated and decided, that should be the end of the matter. Messenger v. Anderson, 225 U. S. 436, 444; Insurance Group v. Denver & R. G. W. R. Co., 329 U. S. 607, 612. It is not applicable here because when the case was first remanded, nothing was finally decided. The whole proceeding thereafter was in fieri. The Commission had a right on reconsideration to make a new record. Ford Motor Co. v. Labor Board, 305 U. S. 364, 374-75. When finally decided, all questions were still open and could be presented. The fact that an appeal could have been taken from the first order of the District Court was not because it was a final adjudication but because a temporary in 186 Opinion of the Court. junction had been granted in order to maintain the status quo. This was an interlocutory order that was appealable because Congress, notwithstanding its interlocutory character, had made it appealable. 28 U. S. C. § 1253. The appellants might have appealed, but they were not bound to. We think that it requires a final judgment to sustain the application of the rule of the law of the case just as it does for the kindred rule of res judicata. Compare United States v. Wallace Co., 336 U. S. 793, 800-801. And although the latter is a uniform rule, the "law of the case" is only a discretionary rule of practice. It is not controlling here. See Southern R. Co. v. Clift, 260 U. S. 316, 319. MR. JUSTICE JACKSON dissents. Judgment reversed. MR. CHIEF JUSTICE VINSON and MR. JUSTICE DOUGLAS took no part in the consideration or decision of this case. Syllabus. 339 U.S. DARR v. BURFORD, WARDEN. CERTIORARI TO THE UNITED STATES COURT OF APPEALS FOR THE TENTH CIRCUIT. No. 51. Submitted December 5, 1949. Decided April 3, 1950. Petitioner, a state prisoner, applied to a Federal District Court for habeas corpus without petitioning this Court for certiorari from a denial of habeas corpus on the merits by the highest state court or excusing his failure to do so. Limiting its consideration of the application solely to the question whether it presented an extraordinary instance that called for disregard of accustomed procedure of petitioning this Court for certiorari, the District Court found that nothing extraordinary appeared and discharged the writ. Held: The District Court properly refused to examine further into the merits of the petition and properly discharged the writ. Pp. 201-219. (a) Ordinarily an application for habeas corpus by one detained under a state court judgment of conviction for crime will be entertained by a federal district court only after all state remedies available, including all appellate remedies in the state courts, have been exhausted and review has been denied by this Court. Ex parte Hawk, 321 U. S. 114. Pp. 203–208. (b) Whatever deviation from the established rule may be inferred from or implied by Wade v. Mayo, 334 U. S. 672, is corrected by this decision. Pp. 208-210. (c) In § 2254 of the 1948 recodification of the Judicial Code, Congress accepted the rule of the Hawk case as a sound rule to guide consideration of habeas corpus in federal courts. Pp. 210214. (d) Though a refusal of certiorari by this Court may carry no weight on the merits upon a later application to a federal district court for habeas corpus, comity ordinarily requires an application for review by this Court before a lower federal court may be asked to intervene in state matters. Pp. 214-217. (e) In this case, petitioner did not sustain the burden of showing that circumstances of peculiar urgency existed to require prompt federal intervention. P. 219. 172 F.2d 668, affirmed. |