delivered the opinion of the court.
Elizabeth Louise Miller was murdered on or about the third day of July, 1921. She left surviving her a mother, three sisters and two brothers. On August 16, 1922, there was filed in the district court an instrument dated January 29, 1921, purporting to be the last will, holographic in form, of Elizabeth Louise Miller. On August 24, 1922, a petition was filed in which the instrument was offered for probate by the contestee, Bertha Josephine Houston, a sister of deceased. Prior to the hearing on the petition the right to receive the purported will was contested by A. E. Farley, Esq., as attorney for two of deceased’s sisters and her two brothers (the mother having died in the meantime), upon the ground that the instrument was a forgery. The cause was tried to the court sitting with a jury, and resulted in a verdict in favor of the contestants and a finding that the will was not entirely written, dated, and signed by Elizabeth Louise Miller. Before *336judgment was rendered, an affidavit on' behalf of contestant was filed, disqualifying Joseph C. Smith, one of the judges of the district court before whom the cause was tried, who, notwithstanding the affidavit, rendered judgment rejecting the purported will and refusing to admit it to probate. Thereafter a motion was made for a new trial, which was denied. It is from the judgment that this appeal is prosecuted.
As ground for reversal, contestee insists that the district judge, having been disqualified after the verdict, was without authority to render judgment. It becomes necessary, then, to determine whether section 8868, Revised Codes of 1921, which provides, “Such affidavit * * * shall be filed with the clerk of the district court * * * at any time before the day appointed or fixed for the hearing or trial of any such action, motion, or proceeding,” permits the filing of a disqualifying affidavit after verdict but before judgment.
This court decided in State ex rel. Carleton v. District Court, 33 Mont. 138, 8 Ann. Cas. 752, 82 Pac. 789, that an affidavit imputing bias and prejudice may be filed after a trial has been had and while a motion for a new trial is pending, at any time before the date set for the hearing of such motion. In. so far as that decision permits a change of judge, when application is made under section 8868 prior to the date set for a hearing upon a motion for new trial upon the ground that it is pro hoc vice a proceeding independent of the trial of the cause on the merits, we have no particular fault to find with it. The rule there announced may not, however, be extended to permit the filing of a disqualifying affidavit after verdict and prior to the entry of judgment. The rendition of judgment is too much a part of the trial of the action on the merits to be characterized as a separate, independent proceeding in the sense that the term is used in the foregoing section. The trial court committed no error in disregarding the affidavit and ren dering judgment.
The contestee urges the insufficiency of contestants’ complaint upon the grounds, first, that it fails to show the con*337testants have such an interest in the estate of Elizabeth Louise Miller as to entitle them to contest the probate of the will; and, second, that it fails to allege authority on the part of A. E. Farley, an attorney at law, to represent contestants.
Without determining whether the complaint, standing alone, sufficiently alleges that the contestants are persons who, but for the will, would succeed in some degree to decedent’s estate, it is clear that the admission in the answer of the contestee “that these contestants are brothers and sisters of said decedent, and owing to the death of the mother are entitled to share equally in the distribution of the estate of the deceased, if the deceased died intestate,’’ remedies any possible infirmity of the character suggested. It is the rule at common law, and it has long been settled in this jurisdiction, that where neces-
sary allegations are omitted from the complaint, but supplied by defendant’s answer, the defect is cured. (1 Chitty on Pleading, 703; Hershfield & Bro. v. Aiken, 3 Mont. 442; Murphy v. Phelps, 12 Mont. 531, 31 Pac. 64; Hamilton v. Great Falls St. Ry. Co., 17 Mont. 334, 42 Pac. 860, 43 Pac. 713; Lynch v. Bechtel, 19 Mont. 548, 48 Pac. 1112; Crowder v. McDonnell, 21 Mont. 367, 54 Pac. 43 ; Hefferlin v. Karlman, 29 Mont. 139, 74 Pac. 201; Grogan v. Valley Trading Co., 30 Mont. 229, 76 Pac. 211; Christiansen v. Aldrich, 30 Mont. 446, 76 Pac. 1007; Mantle v. White, 47 Mont. 234, 132 Pac. 22; Stephens v. Conley, 48 Mont. 352, Ann. Cas. 1915D, 958, 138 Pac. 189; Buhler v. Loftus, 53 Mont. 546, 165 Pac. 601; Kummrow v. Bank of Fergus County, 57 Mont. 390, 188 Pac. 649; Hurley v. Great Falls Baseball Assn., 59 Mont. 21, 195 Pac. 559; Sevanin v. Chicago, M. & St. P. Ry. Co., 62 Mont. 546, 205 Pac. 825; Anderson v. Wirkman, 67 Mont. 176, 215 Pac. 224; 1 Sutherland on Code Pleading, Practice and Forms, see. 361; Bliss on Code Pleading, 3d ed., see. 437; Pomeroy on Code Remedies, 579; 31 Cyc. 714.)
The contention that the complaint must allege that Mr. Farley was the attorney for the contestants is without merit. Heirs at law may contest a will through attorneys appointed by them. *338(Sec. 10029, Rev. Codes 1921.) And it is presumed without allegation or proof that an attorney at law who represents a client does so with his consent and by virtue of his retainer. (Pullen v. City of Butte, 45 Mont. 46, 121 Pac. 878; Davenport v. Davenport, 69 Mont. 405, 222 Pac. 422; Strand Improvement Co. v. City of Long Beach, 173 Cal. 765, 161 Pac. 975; Drew v. Burley (D. C.), 287 Fed. 916; Gila Valley El., Gas & Water Co. v. Arizona Trust & Sav. Bank, 25 Ariz. 177, 215 Pac. 159; Jordan v. Evans, 99 Neb. 666, 157 N. W. 620; Miller v. Continental Assur. Co., 233 Mo. 91, Ann. Cas. 1912C, 102, 134 S. W.) 1003; Keithley v. County of Clark, 206 Ill. App. 500.) “The universal rule is that, where an attorney appears and undertakes to act for another in a capacity and for a purpose within the scope of the ordinary powers of a duly licensed practitioner, his authority so to act will be presumed.” (1 Thornton on Attorneys, sec. 230.)
If the eontestee desired to question the right of Mr. Farley to represent contestants, she should have applied to the trial court at the earliest opportunity for an order requiring him to produce and prove the authority under which he appeared, in accordance with the provisions of section 8994 of the Revised Codes of 1921. His authority to represent the contestants not having been challenged in the district court, the right to attack it later was waived. (Missoula Belt Line Ry. Co. v. Smith, 58 Mont. 432, 442, 193 Pac. 529; 6 C. J. 631; Smith v. Smith, 145 Cal. 615, 79 Pac. 275; Brown v. Arnold, 131 Fed. 723, 67 C. C. A. 125.)
Error is predicated upon the ruling of the trial court in permitting M. F. McDonald, a witness for contestants, to testify, over objection, with reference to the signature of the purported will, as follows: “ Q. Did you compare that with any other papers you knew to be genuine? A. Yes. Q. I will ask you to state your opinion based upon your comparison as to whether or not, in your opinion, that is the handwriting of Mrs. Louise Miller? A. It is not.” Contestee also assigns as error the court’s ruling in permitting other witnesses, over *339objection, to give their opinion as to the genuineness of the handwriting of the purported will, based upon a comparison with other writings in evidence admitted to be genuine. These assignments of error involve the same legal principles and will be treated together.
Section 10592, Revised Codes of 1921, provides as follows: “Evidence respecting the handwriting may also be given by comparison, made by the witness or jury, with writings admitted or treated as genuine by the party against whom the evidence is offered, or proved to be genuine to the satisfaction of the judge.” This section was adopted from the California statutes after the supreme court of that state had construed the term “witness” to mean expert witness. (Goldstein v. Black, 50 Cal. 462; Spottiswood v. Weir, 80 Cal. 448, 22 Pac. 289.) It is to be presumed, under the rule consistently adhered to by this court, that we adopted the construction thus placed upon it as a part of the law itself. (Territory v. Stears, 2 Mont. 324; Lindley v. Davis, 6 Mont. 453, 13 Pac. 118; First National Bank of Butte v. Bell etc. Min. Co., 8 Mont. 32, 19 Pac. 403; Price v. Lush, 10 Mont. 61, 9 L. R. A. 467, 24 Pac. 749; Stackpole v. Hallahan, 16 Mont. 40, 28 L. R. A. 502, 40 Pac. 80; Murray v. Heinze, 17 Mont. 353, 42 Pac. 1057, 43 Pac. 714; Largey v. Chapman, 18 Mont. 563, 46 Pac. 808; Stadler v. First National Bank, 22 Mont. 190, 74 Am. St. Rep. 582, 56 Pac. 111; Butte & Boston Con. Min. Co. v. Montana Ore Pur. Co., 25 Mont. 41, 63 Pac. 825; Winslow v. Dundom, 46 Mont. 71, 125 Pac. 136; Miller v. Miller, 47 Mont. 150, 131 Pac. 23; Moreland v. Monarch Min. Co., 55 Mont. 419, 178 Pac. 175; State ex rel. Rankin v. State Board of Examiners, 59 Mont. 557, 197 Pac. 988; Mares v. Mares, 60 Mont. 36, 199 Pac. 267; State ex rel. Murray v. Walker, 64 Mont. 226, 210 Pac. 90; Winnett Pacific Oil Co. v. Wilson, 71 Mont. 250, 229 Pac. 850.) A nonexpei't witness may give an opinion as to the handwriting of a person whom he has seen write, or when he has seen writings purporting to be his, upon which he has acted or been charged, and who has thus acquired a knowl*340edge of Ms handwriting (sec. 10591, Rev. Codes 1921), or he may refresh his memory by examining other writings known or admitted to be genuine (22 C. J. 630), but he cannot give his opinion based upon a comparison of writings in regard to which the jury are equally capable of forming an opinion from the writings in evidence (Spottiswood v. Weir, supra; Johnston v. Bee, 84 W. Va. 532, 7 A. L. R. 252, 100 S. E. 486; Griffin v. State, 90 Ala. 596, 8 South. 670; Griffin v. Working Women’s Home Assn., 151 Ala. 597, 44 South. 605; Mixer v. Bennett, 70 Iowa, 329, 30 N. W. 587). It was reversible error for the trial court to admit'the evidence.
It is insisted that the trial court erred in permitting the witness George Allen to answer the following question over the objection of the contestes: “Q. I will ask you, from your acquaintance with Mrs. Louise Miller, your knowledge of her association and dealings with different banks in the state of Montana, her dealings with yourself as an attorney, and your knowledge as to the ordinary form of a holographic will, from your reading of the different law books, whether or not it is probable or improbable for a woman in the condition that Mrs. Louise Miller was in, to execute such an instrument?” The witness answered that in his opinion it was improbable that deceased “prepared and wrote” the purported will. 'Contention is made that the subject is not one calling for expert testimony, and with this we agree. “The theory upon which expert testimony is held competent is that there are persons whose knowledge of a science, art or trade being superior to that of the mass of mankind, qualifies them to express an opinion upon any matter pertaining thereto.” (De Sandro v. Missoula Light etc. Co., 52 Mont. 333, 157 Pac. 641.) When, however, it can be said as a matter of law that the jurors are equally capable of forming an opinion or can draw, or can readily be directed how to draw, a reasonable inference, then the matter is not the subject of expert testimony. (Coleman v. Perry, 28 Mont. 1, 72 Pac. 42; Copenhaver v. Northern Pac. By. Co., 42 Mont. 453, 113 Pac. 467; Westlake v. *341Keating Gold Min. Co., 48 Mont. 120, 136 Pac. 38.) In other words, when the conclusions to 'be drawn from the facts stated are within the range of ordinary training, intelligence and common observation, expert testimony is not admissible. (Kelley v. John R. Daily Co., 56 Mont. 63, 181 Pac. 326; State v. Keeland, 39 Mont. 506, 104 Pac. 513; 22 C. J. 642.) “‘The necessity for opinion evidence only exists where the facts in controversy are incapable of being detailed and described so as to give the jury an intelligible understanding concerning them; but when the facts are such as can be detailed or described, and the jury are able to understand and draw a correct conclusion from them without such opinion evidence, the necessity for it does not exist.’ ” (Cummings v. Reins Copper Co., 40 Mont. 599, 621, 107 Pac. 904.) Manifestly this testimony elicited from George Allen should have been excluded under the rules governing the admission of opinion evidence, and it was prejudicial error to receive it.
I Inasmuch as a new trial must be granted, it is proper to consider contestants’ contention that the court erred in excluding their exhibits 5, 6 and 7, each of which is a letter written by deceased, containing declarations as to her feelings and attitude toward the contestes. Exhibit 5 is dated February 2, 1921, which is four days after the date of the purported will. Exhibits 6 and 7 are undated but disclose upon examination that they are in no sense a part of the res gestae. .In our opinion these exhibits were properly excluded. The 'declarations of the deceased in all of the exhibits do not come ¡within any exception to the law excluding hearsay evidence upon the trial of an action. They are not declarations against interest. The will could not take effect until after her ¡death, and therefore the declarations had no effect upon her ■interest. (In re Colbert’s Estate, 31 Mont. 461, 107 Am. St. Rep. 439, 3 Ann. Cas. 952, 78 Pac. 971, 80 Pac. 248.) "We 'think the correct rule of law applicable to the admission of ^declarations of this character is stated concisely by the supreme court of the United States in the case of Throckmorton *342v. Holt, 180 U. S. 552, 45 L. Ed. 663, 21 Sup. Ct. Rep. 474, speaking through Mr. Justice Peckham: “When they are not a part of the res gestae, declarations of this nature are excluded because they are unsworn, being hearsay only, and where they are claimed to be admissible on the ground that they are said to indicate the condition of mind of the deceased with regard to his affections, they are still unsworn declarations, and they cannot be admitted if other unsworn declarations are excluded. In other words, there is no ground for an exception in favor of the admissibility of declarations of a deceased person as to the state of his affections, when the mental or testamentary capacity of the deceased is not in issue.” (In re Colbert’s Estate, supra.)
The judgment is reversed and the cause remanded for a new trial.
Reversed and remanded.
Associate Justices Holloway, Galen and Stark concur. Mr. Chibe Justice Callaway, being disqualified, did not hear the argument and takes no part in the foregoing decision.