At the time of the occurrence of the injury the company was a common car rier by rail, engaged in interstate and intrastate commerce, and that at such time there was a draft of freight cars attached to the engine, which was in charge of the crew of which Polk was a member. Some of these cars were bound from points within the state to other points within the state, and the others were loaded with various commodities, some of which were bound from points outside of the state to points within the state, and others of which were bound from points within the state to points outside of the state, and there was at least one car of this draft which was passing through the state from a point in New York to a point in Illinois. The board, upon the appeal of the company, adopted the findings of fact and conclusions of law of the referee, and affirmed his award. This action was affirmed by the court of common pleas, and the latter's judgment by the supreme court.

performed on a train constituted of interstate and intrastate commerce were performed in the latter commerce. The presumption, indeed, might be the other way. It is to be remembered that it is the declaration of the cases that, if there is an element of interstate commerce in a traffic or employment, it determines the remedy of the employee. Second Employers' Liability Cases (Mondou v. New York, N. H. & H. R. Co.) 223 U. S. 1, 56 L. ed. 327, 38 L.R.A.(N.S.) 44, 32 Sup. Ct. Rep. 169, 1 N. C. C. A. 875; New York C. R. Co. v. Winfield, 244 U. S. 147, 61 L. ed. 1045, L.R.A. 1918C, 439, 37 Sup. Ct. Rep. 546, Ann. Cas. 1917D, 1139, 14 N. C. C. A. 680.

Northern P. R. Co. v. Washington, 222 U. S. 370, 375, 56 L. ed. 237, 238, 52 Sup. Ct. Rep. 160, declares and illustrates the principle. Expressing the facts and the law applicable to them, it was said: "The train, although moving from one point to another in the state of Washington, was hauling merchandise from points outside of the state, destined to points within the state, and from points within the state to points in Brit

The referee did not find definitely as a fact that Polk was engaged in intrastate commerce at the time of his in-ish Columbia. . . . This transportajury, but assumed that the fact might be so; therefore, regarded it as so, because, in his, the referee's, opinion, the burden of proving the contrary, that is, that Polk "was actually engaged in work incident to interstate commerce," was upon the company, and the company had "not met the burden required of it;" and further, that the company "offered no testimony whatever to show what work John M. Polk was performing at the time he was injured;

."

The supreme court approved the findings and the [334] deductions from them. It is manifest, therefore, that the case is within the rule of Philadelphia & R. R. Co. v. Di Donato, just decided [256 U. S. 327, ante, 955, 41 Sup. Ct. Rep. 516.] Here, as there, the employment concerned both kinds of commerces, and was to be exercised as much on one as on the other. In other words, was as much and as intimately directed to the interstate cars and freight as to the intrastate cars and freight, and that there might have been some duties directed to the latter, though there is no evidence of it, is the suggestion of a speculation that has no tangible prompting in the

case.

Besides, we cannot accede to the view that there is a presumption that duties

tion was interstate commerce, and the train was an interstate train, despite the fact that it may also have been carrying some local freight. In view of the unity and indivisibility of the service of the train crew, and the paramount character of the authority of Congress to regulate commerce, the act of Congress was exclusively controlling. Southern R. Co. v. United States, 222 U. S. 20, 56 L. ed. 72, 32 Sup. Ct. Rep. 2, 3 N. C. C. A. 822."

[335] It would seem indisputable, therefore, if there be an assertion of the claim or remedy growing out of an occurrence in which there are constituents of interstate commerce, the burden of explanation and avoidance is on him who asserts the claim or remedy, not on the railway company to which it is directed, and there is nothing in Osborne v. Gray, 241 U. S. 16, 60 L. ed. 865, 36 Sup. Ct. Rep. 486, in opposition. Indeed, the court was asked in that case to do what the referee and the supreme court in this case have done; that is, to assume to know things of which there is no evidence.

Judgment reversed and cause remanded for further proceedings not inconsistent with this opinion.

Mr. Justice Clarke dissents.

Argued November 19, 1920. Decided May 23 Am. Dec. 431; 4 Bl. Com. 180; 1

On standpoints of determination as to The common law never recognized two danger and necessity to kill in self-de-species of homicide in self-defense, one fense-see note to State v. Beckner, 3 L.R.A. (N.S.) 535.

case where public interests, e. g., aid of justice, were not involved, required the assaulted person to avoid homicide, if he could do so without endangering the life of himself or another.

dockyard, or other needful building," al-
though it does allege that it was acquired
from the state of Texas by the United
States for the exclusive use of the United
States for its public purposes, and was
under the exclusive jurisdiction of the
same. Penal Code of March, 4, 1909,
chap. 321, § 272, subd. 3, 35 Stat. at L

Anno. 2d ed. p. 890. [342] Constitu-
tion, art. 1, § 8. In view of our opinion
upon the second point, we think it un-
necessary to do more than to refer to
the discussion in the court below upon
this.

The other question concerns the in-
structions at the trial. There had been
trouble between Hermis and the defend-
ant for a long time. There was evidence
that Hermis had twice assaulted the de-

3 Bracton (1250) Twiss ed. chap. 5, f. 104b, f, 134, 144b; 2 Pollock & M. History of Eng. Law, pp. 476-481; 3 Stephen, History of Crim. Law, pp. 36-1088, Comp. Stat. § 10,445, 7 Fed. Stat. 41; Beale, Retreat from a Murderous Assault, 16 Harvard L. Rev. 567; Britton (1290) chap. VI. p. 34; Bracton's Note Book, Nos. 1084, 1215; Howel's Case, Kenny, Cases on Crim. Law, p. 139; Y. B. 30, 31, Edw. I. 510, 512 (1302); Fitzherbert, Abr. title, "Corone," Nos. 261, 284-287, 305 (1330) translated in 16 Harvard L. Rev. 569; Kenny Cases on Crim. Law, pp. 141, 142; Compton's Case, 22 Lib. Ass. 97, pl. 55, translated in 16 Harvard L. Rev. 569; Cooper's fendant with a knife, and had made Case, Cro. Car. 544, 79 Eng. Reprint, 1069; 3 Co. Inst. chap. 8, p. 55; 1 Hale, P. C. pp. 424, 425, 478; Daver's Case, Godb. 288, 78 Eng. Reprint, 169; Calfielde v. Keeper, Rolle, Rep. 189, 81 Eng. Reprint, 422; 1 Hawk P. C. pp. 104-115; Pond v. People, 8 Mich. 177; Morse's Case, 4 Cr. App. Cas. 50; Aldrich v. Wright, 53 N. H. 401, 16 Am. Rep. 339; Reg. v. Smith, 8 Car. & P. 160; Reg. v. Bull, 9 Car. & P. 22; Reg. v. Knock, 14 Cox, C. C. 1; Reg. v. Rose, 15 Cox, C. C. 540; Reg. v. Symondson, 60 J. P. 645; United States v. Wiltberger, 3 Wash. C. C. 521, Fed. Cas. No. 16,738; United States v. Outerbridge, 5 Sawy. 620, Fed. Cas. No. 15,978; United States v. Mingo, 2 Curt. C. C. 5 Fed. Cas. No. 15,781; United States v. King, 34 Fed. 308; United States v. Lewis, 111 Fed. 635; Allen v. United States, 164 U. S. 492, 497, 41 L. ed. 528, 529, 17 Sup. Ct. Rep. 154; Anderson v. United States, 170 U. S. 481, 508, 42 L. ed. 1116, 1125, 18 Sup. Ct. Rep. 689.

The petitioner was convicted of murder in the second degree, committed upon one Hermis at a place in Texas within the exclusive jurisdiction of the United States, and the judgment was affirmed by the circuit court of appeals. 168 C. C. A. 258, 257 Fed. 46. A writ of certiorari was granted by this court. 250 U. S. 637, 63 L. ed. 1183, 39 Sup. Ct. Rep. 494. Two questions are raised. The first is whether the indictment is sufficient, inasmuch as it does not allege that the place of the homicide was acquired by the United States "for the erection of a fort, magazine, arsenal,

threats, communicated to the defendant,
that the next time, one of them would
go off in a black box. On the day in
question the defendant was at the place
above mentioned, superintending excava-
tion work for a postoffice. In view of
Hermis's threats he had taken a pistol
with him, and had laid it in his coat
upon a dump. Hermis was driven up
by a witness, in a cart to be loaded, and
the defendant said that certain earth
was not to be removed, whereupon Her-
mis came toward him, the defendant
says, with a knife. The defendant re-
treated some 20 or 25 feet to where his
coat was, and got his pistol. Hermis
was striking at him, and the defendant
fired four shots and killed him.
judge instructed the jury, among other
things, that "it is necessary to remember,
in considering the question of self-de-
fense, that the party assaulted is always
under the obligation to retreat so long
as retreat is open to him, provided that
he can do so without subjecting himself
to the danger of death or great bodily

The

harm." The instruction was reinforced.
by the further intimation that unless
"retreat would have appeared to a man
of reasonable prudence, in the position
of the defendant, as involving danger of
death or serious bodily harm," the de-

fendant was not entitled to stand his
ground. An instruction to the effect
that if the defendant had reasonable
grounds of apprehension that he was in
danger of losing his life or of suffering
serious bodily harm from Hermis, he
was not bound to retreat, was refused.
So the question is brought out with suffi-
cient clearness whether the formula
[343] laid down by the court, and often

1

repeated by the ancient law, is adequate here was at a place where he was called to the protection of the defendant's to be, in the discharge of his duty. rights. There was evidence that the last shot was fired after Hermis was down. The jury might not believe the defendant's testimony that it was an accidental discharge, but the suggestion of the government, that this court may disregard the considerable body of evidence that the shooting was in self-defense, is based upon a misunderstanding of what was meant by some language in Battle v. United States, 209 U. S. 36, 38, 52 L. ed. 670, 672, 28 Sup. Ct. Rep. 422. Moreover, if the last shot was intentional, and may seem to have been unnecessary when considered in cold blood, the defendant would not necessarily lose his immunity if it followed close upon the others, while the heat of the conflict was on, and if the defendant believed that he was fighting for his life.

It is useless to go into the developments of the law from the time when a man who had killed another, no matter how innocently, had to get his pardon, whether of grace or of course. Concrete cases or illustrations stated in the early law in conditions very different from the present, like the reference to retreat in 3 Co. Inst. 55, and elsewhere, have had a tendency to ossify into specific rules without much regard for reason. Other examples may be found in the law as to trespass ab initio (Com. v. Rubin, 165 Mass. 453, 43 N. E. 200), and as to fresh complaint after rape (Com. v. Cleary, 172 Mass. 175, 51 N. E. 746). Rationally, the failure to retreat is a circumstance to be considered with all the others in order to determine whether the defendant went farther than he was justified in doing; not a categorical proof of guilt. The law has grown, and even if historical mistakes have contributed to its growth, it has tended in the direction of rules consistent with human nature. Many respectable writers agree that if a man reasonably believes that he is in immediate danger of death or grievous bodily harm from his assailant, he may stand his ground, and that if he kills him, he has not exceeded the bounds of lawful self-defense. That has been the decision of this court. Beard v. United States, 158 U.S. 550, 559, 39 L. ed. 1086, 1090, 15 Sup. Ct. Rep. 962, 9 Am. Crim. Rep. 324. Detached reflection cannot be demanded in the presence of an uplifted knife. Therefore, in this court, at least, it is not a condition of immunity that one in that situation should pause to consider whether a reasonable man might not think it possible to fly with safety, or to disable his assailant rather than to kill him. Rowe v. United States, 164 U. S. 546, 558, 41 L. ed. 547, 551, 17 Sup. Ct. Rep. 172. The law of Texas very strongly adopts these views, as is shown by many cases, of which it is enough to cite two: Cooper v. State, 49 Tex. Crim. Rep. 28, 96 S. W. 1068; Baltrip v. State, 30 Tex. App. 545, 549, 17 S. W. 1106.

The government presents a different case. It denies that Hermis had a knife, and even that Brown was acting in selfdefense. Notwithstanding the repeated threats of Hermis, and intimations that one of the two would die at the next encounter, which seem hardly to be denied, of course it was possible for the jury to find that Brown had not sufficient reason to think that his life was in danger at that time, that he exceeded the limits of reasonable self-defense, or even that he was the attacking party. But upon the hypothesis, to which the evidence gave much color, that Hermis began the attack, the instruction that we have stated was wrong. Judgment reversed.

Mr. Justice Pitney and Mr. Justice Clarke dissent.

relation to Federal government- right to regulate descent and distribution validity of Federal estate tax.

1. The rights of the several states to regulate descent and distribution are not

[344] It is true that in the case of Beard, he was upon his own land (not in his house), and in that of Rowe, he was in the room of a hotel; but those facts, although mentioned by the court, would not have bettered the defense by the old common law, and were not appreciably more favorable than that the defendant 4 L.R.A. 171; Com. v. Ferguson, 10

Note. As to taxes on succession and collateral inheritances-see notes to Re Howe, 2 L.R.A. 825; Wallace v. Myers,

State, 25 S. D. 369, 33 L.R.A.(N.S.) 606, 126 N. W. 611; Knox v. Emerson, 123 Tenn. 409, 131 S. W. 972; Dixon v. Ricketts, 26 Utah, 215, 72 Pac. 947; Schoolfield v. Lynchburg, 78 Va. 366; Re Joyslin, 76 Vt. 88, 56 Atl. 281; State v. Clark, 30 Wash. 439, 71 Pac. 20; Nunnemacher v. State, 129 Wis. 190, 9 L.R.A. (N.S.) 121, 108 N. W. 627, 9 Ann. Cas. 711.

Sovereign power to regulate any subject-matter may have (a) positive expression in rules, requirements, or requisitions established by legislative authority, or (b) negative expression in the absence of such rules, requirements, or requisitions; the absence of any particular class of rules, requirements, or requisitions indicating the legislative will that, in that aspect, the subjectmatter shall be free from regulative restraint and requisition. The sovereign power of a state to regulate descent and distribution will always be found to have been expressed, in the matter of the requisition of death duties of the kind which are essentially a manifestation of such power, either (a) in the requisition of such death duties, or (b) in the absence of any such requisition; thus indicating the will of the state that there shall be no such requisition.

cago Title & T. Co. 187 Ill. 42, 58 N. E. 318; Re Speed, 216 Ill. 23, 108 Am. St. Rep. 189, 74 N. E. 809, affirmed in 203 U. S. 553, 51 L. ed. 314, 27 Sup. Ct. Rep. 171, 8 Ann. Cas. 157; Re Graves, 242 Ill. 212, 89 N. E. 879; People v. Griffith, 245 II. 532, 92 N. E. 313; National Safe Deposit Co. v. Stead, 250 Ill. 584, 95 N. E. 973, Ann. Cas. 1912B, 430, affirmed in 232 U. S. 58, 58 L. ed. 504, 34 Sup. Ct. Rep. 209; Northern Trust Co. v. Buck & Rayner, 263 Ill. 222, 104 N. E. 1114; Arnaud's Heirs v. His Executor, 3 La. 336; Kohn's Succession, 115 La. Ann. 71, 38 So. 898; Levy's Succession, 115 La. Ann. 377, 8 L.R.A. (N.S.) 1180, 39 So. 37, 5 Ann. Cas. 871; Westefeldt's Succession, 122 La. Ann. 836, 48 So. 281; Fisher v. State, 106 Md. 104, 66 Atl. 661; Washington County Hospital Asso. v. Mealey, 121 Md. 274, 48 L.R.A.(N.S.) 373, 88 Atl. 136, Ann. Cas. 1915B, 1050; Minot v. Winthrop, 162 Mass. 113, 26 L.R.A. 259, 38 N. E. 512; Emmons v. Shaw, 171 Mass. 410, 50 N. E. 1033; Crocker v. Shaw, 174 Mass. 266, 54 N. E. 549; Frothingham v. Shaw, 175 Mass. 59, 78 Am. St. Rep. 475, 55 N. E. 623; Atty. Gen. v. Stone, 209 Mass. 186, 95 N. E. 395; Atty. Gen. v. Clark, 222 Mass. 291, L.R.A.1916C, 679, 110 N. E. 299, Ann. Cas. 1917B, 119; Union Trust Co. v. Wayne Probate Gibbons v. Ogden, 9 Wheat. 1, 209, Judge, 125 Mich. 487, 84 N. W. 1101; 6 L. ed. 23, 73; Gloucester Ferry Co. State ex rel. Gage v. Probate Ct. 112 v. Pennsylvania, 114 U. S. 196, 203, 204, Minn. 279, 128 N. W. 18; State ex rel. 29 L. ed. 158, 161, 162, 1 Inters. Com. Fath v. Henderson, 160 Mo. 190, 60 S. Rep. 382, 5 Sup. Ct. Rep. 826; Hammer W. 1093; Maguire v. University of Mis- v. Dagenhart, 247 U. S. 251, 269, 62 L. souri, 271 Mo. 359, 196 S. W. 737; Reed. 1101, 1104, 3 A.L.R. 649, 38 Sup. Cupple, 272 Mo. 465, 199 S. W. 556; Ct. Rep. 529, Ann. Cas. 1918E, 724; Gelsthorpe v. Furnell, 20 Mont. 299, 39 Passenger Cases, 7 How. 283, 399, 12 L.R.A. 170, 51 Pac. 267; Re Touhy, 35 L. ed. 702, 750. Mont. 431, 90 Pac. 170; State ex rel. Floyd v. District Ct. 41 Mont. 357, 109 Pac. 438; Howell v. Edwards, 88 N. J. L. 134, 96 Atl. 186; Re Hamilton, 148 N. Y. 310, 42 N. E. 717; Re Sherman, 153 N. Y. 1, 46 N. E. 1032; Re Dows, 167 N. Y. 227, 52 L.R.A. 433, 88 Am. St. Rep. 508, 60 N. E. 439; Re Delano, 176 N. Y. 486, 64 L.R.A. 279, 68 N. E. 871; Re Lansing, 182 N. Y. 238, 74 N. E. 882; Re White, 208 N. Y. 64, 46 L.R.A. (N.S.) 714, 101 N. E. 793, Ann. Cas. 1914D, 75; Re Zborowski, 213 N. Y. 109, 107 N. E. 44; Re Penfold, 216 N. Y. 163, 110 N. E. 497, Ann. Cas. 1916A, 783; Alvany v. Powell, 55 N. C. (2 Jones, Eq.) 51; Re Morris, 138 N. C. 259, 50 S. E. 682; Finnen's Estate, 196 Pa. 72, 46 Atl. 269; Jewell's Estate, 235 Pa. 119, 83 Atl. 610; Jackson v. Myers, 257 Pa. 104, L.R.A. 1917F, 821, 101 Atl. 341; Sherman v.

The taxing power of the United States cannot constitutionally be so exercised as to amount to a usurpation of any sovereign power belonging to the states. If the United States have attempted to impose death duties in a form in which such requisitions are essentially a manifestation of the sovereign power to regulate descent and distribution, this is an attempted usurpation of a sovereign power belonging to the states.

Knowlton v. Moore, 178 U. S. 41, 59, 44 L. ed. 969, 977, 20 Sup. Ct. Rep. 747; Gloucester Ferry Co. v. Pennsylvania, 114 U. S. 196, 214, 29 L. ed. 158, 165, 1 Inters. Com. Rep. 382, 5 Sup. Ct. Rep. 826; Pullman Co. v. Kansas, 216 U. S. 56, 54 L. ed. 378, 30 Sup. Ct. Rep. 232, reversing 75 Kan. 664, 90 Pac. 319; Ludwig v. Western U. Teleg. Co. 216 U. S. 146, 162, 54 L. ed. 423, 429,