Under tbe pleadings and tbe form of tbe issue submitted to tbe jury, tbe burden of proof was on the plaintiff to make out her case. It is conceded that a prima facie right of recovery was established by her evidence. Williamson v. Ins. Co., ante, 377. Tbe duty of meeting tbis prima facie case, in order to avoid hazarding an adverse verdict, was then cast upon tbe defendant. Lyons v. Knights of Pythias, 172 N. C., 408, 90 S. E., 423; Harris v. Junior Order, 168 N. C., 357, 84 S. E., 405; Wilkie v. National Council, 147 N. C., 637, 61 S. E., 580; Doggett v. Golden Gross, 126 N. C., 477, 36 S. E., 26. Tbis, however, did not change tbe burden of proof or tbe burden of tbe issue. Brock v. Ins. Co., 156 N. C., 112, 72 S. E., 213.
Tbe burden of tbe issue does not shift, but tbe duty of going forward with evidence, to avoid tbe hazard or chance of an adverse verdict, may shift from side to side as tbe case progresses, according to tbe nature and strength of tbe proofs offered in support or denial of tbe main fact in issue. White v. Hines, 182 N. C., 275, 109 S. E., 31; Winslow v. Hardwood Co., 147 N. C., 275, 60 S. E., 1130. Tbe burden of proof continues to rest upon tbe party who, either as plaintiff or defendant, affirmatively alleges facts necessary for him to prevail in tbe case. It is required of him who thus asserts such facts to establish them before he can become entitled to a verdict in bis favor; and, as to these matters, be constantly has tbe burden of tbe issue, whatever may be tbe intervening effect of different kinds of evidence, or evidence possessing, under tbe law, varying degrees of probative force. Smith v. Hill, 232 Mass., 188.
Tbe defendant, of course, has tbe burden of establishing all affirmative defenses, whether they relate to tbe whole case or only to certain issues in tbe case. As to such defenses, he is tbe actor and has tbe *518laboring oar. Austin v. R. R., 187 N. C., 7, 121 S. E., 1; Shepard v. Tel. Co., 143 N. C., 244, 55 S. E., 704.
Wbat is and what is not an affirmative defense is not always easy to determine. Sometimes it is to be determined by the pleadings and at others by presumptions arising from the evidence adduced on the hearing or from admissions made during the trial. Spilene v. Mfg. Co., 79 N. H., 326. Here the defendant relies upon a defense, affirmative in form perhaps, but which in reality merely traverses the allegations of the complaint.
It is true that in some of the cases expressions are to be found which may seem to justify the court’s charge to the jury, unless confined to the particular fact situations there presented, but “the duty of the defendant to go forward with his proof” is not to be confused with the burden of proof or the burden of the issue. Page v. Mfg. Co., 180 N. C., 330, 104 S. E., 667.
The distinction between the burden of proof and the duty of going forward with evidence was investigated in the case of Speas v. Bank, 188 N. C., 524, 125 S. E., 398. Much that was there said would seem to be applicable here.
The rule as to the burden of proof constitutes a substantial right, for upon it many cases are made to turn, and its erroneous placing is reversible error. DeHart v. Jenkins, 211 N. C., 314, 190 S. E., 218; Boone v. Collins, 202 N. C., 12, 161 S. E., 543; Hosiery Co. v. Express Co., 184 N. C., 478, 114 S. E., 823.
For the error, as indicated, a new trial must be awarded.
New trial.