DEICE, J.
Appellant was convicted in tbe district court of Weber County, Utab, of tbe crime denounced by section 4221, Comp. Laws 1901, wbicb reads as follows: “Any person wbo shall carnally and unlawfully know any female over tbe age of thirteen years and under tbe age of eighteen years shall be guilty of a felony.” Tbe female in question, hereinafter designated prosecutrix, was sixteen years of age when tbe sexual act complained of occurred.
Tbe appellant, in substance, contends that tbe evidence is insufficient to sustain tbe judgment of conviction, and that tbe court erred in overruling bis motion for a new trial. One of tbe grounds of tbe motion wbicb is strenuously insisted upon is based upon newly discovered evidence. Concerning the contention that tbe judgment is not sustained by sufficient evidence, it is sufficient to say that tbe evidence with regard to tbe sexual act is in direct conflict. *517The prosecutrix most emphatically stated in her testimony that the appellant, on or about tbe 16th day of August, 1908, had sexual intercourse with her while she and he were out riding together in his buggy; that she never had sexual intercourse with any one else either before or after the act in question, while appellant, upon the other hand, just as emphatically denies such intercourse either on that occasion or at any other time. There are some facts in evidence which, to some extent, tend to corroborate the prosecutrix, while the evidence in corroboration of appellant’s claims is much stronger. In view of the circumstances there is no escape from the conclusion that neither the prosecutrix nor the appellant could be mistaken with regard to whether the sexual act took place or not. They either had or did not have the sexual intercourse as testified to by the prosecutrix. This, no doubt, is the view the jury entertained, and thus concluded that, under all the circumstances, the statements of the prosecutrix were more worthy of belief than were those of the appellant and his witnesses, none of whom, except the appellant, were' present when the alleged offense was committed.
The question with respect to the weight of the evidence was fully and fairly submitted to the jury, and in view that there is substantial evidence in support of their verdict we are powerless to interfere. Moreover, the tidal court, after having heard and seen the witnesses testify has approved the finding of the jury, and we must assume that he did so because he was satisfied with the result. It is elementary that, in granting or refusing motions for new trials, a certain amount of discretion is vested in the trial courts which they alone can exercise. This court may not usurp the functions of the trial courts and exercise this dis- 1,2, 3 cretion for them in granting motions for new trials, and grant them whenever in our judgment, from a mere inspection of the record, a new trial should have been granted. Before we can reverse a judgment some good, legal cause therefor must affirmatively be made to appear. Nor can we, under the guise of reviewing an alleged1 abuse of *518discretion of tbe trial court, pass upon tbe weight of tbe effect of tbe evidence. If there is substantial evidence in support of tbe verdict, we are powerless to interfere with it, except upon questions of law. This is tbe clear import of our Constitution and has become tbe settled policy of this court as appears from tbe following, among other cases: State v. Moore, 36 Utah, 521, 105 Pac. 293; State v. Endsley, 19 Utah, 478, 57 Pac. 430; State v. Webb, 18 Utah, 441, 56 Pac. 159; State v. Halford, 17 Utah, 475, 54 Pac. 819; State v. McCune, 16 Utah, 174, 51 Pac. 818. Prom tbe foregoing it follows that we cannot disturb tbe judgment upon tbe first ground referred to.
At tbe trial of tbe case a physician was called as a witness who testified on behalf of tbe state that at tbe time of tbe trial tbe prosecutrix was pregnant and that she bad been so for a period of about five or five and' one-half months, and that be could fix tbe time of conception within about one-balf month. The trial took place on tbe 9th day of February, 1909, and as we have seen, the sexual act in issue; as testified to by tbe prosecutrix, occurred on or about tbe 16th day of August, 1908, or not quite six months before tbe trial. Two physicians filed affidavits in support of tbe motion for a new trial from which it, in substance, is made to appear that tbe prosecutrix was delivered of a child on tbe 28th day of March, 1909, and that on tbe 9th day of April following tbe said physicians examined said child. One of tbe physicians in bis affidavit says “that said child, if not a full-term child, was about an eight-months child; that is, said child was born a period of about eight months after date of conception.” The other physician testified “that said child, if not a full-term child, was not less than an eight-months child.” It is contended that in view of the testimony of the prosecutrix, she must have conceived on August 16, 1908; that from that date to the date of the birth of the child is only about seven and one-half months, in fact a few days less than that; that if the child was an eight-months child, as the physicians state it was, then the sexual act complained of could not have taken place as the prosecu-*519trix testified it did, and bence it is contended sbe is further contradicted by these circumstances, and the appellant’s testimony is correspondingly corroborated thereby. This does not necessarily follow. True, the normal period of gestation of the human species, as known and recorded for over 3000 years, is from 270 to 280 days, or approximately nine calendar months. It is equally well known that some births occur within a much shorter period, and while such occurrences are not frequent they do sometimes occur in a shorter time even than was the case this instance. Peterson v. People, 74 Ill. App. 178; Hull v. State, 93 Ind. 128. It will be observed that neither of the physicians (who, we must assume, made the strongest possible statement, they could in their affidavits in behalf of appellant) says that the child of which the prosecutrix was delivered on March 28, 1909, was a full-term child, but they in effect testify that it was about an eight-months child. The exact time that elapsed between August 16, 1908, the date of the alleged sexual act, and the date of the birth of the child, was 225 days, or, if expressed in months, about seven and one-half months. From the affidavits of the two physicians it is also made to appear that they did not see and examine the child until the 9th day of April, 1909, or nearly two weeks after it was bom. The fact that they say that if the child was not a full-term child it was about an eight-months child may thus, in a measure at least, be accounted for. At all events it does affect the weight to be given to their statements. Moreover, to use the term “about eight months” is not far from saying seven and one-half months. There is, therefore, no serious conflict between the facts stated by the physicians in their affidavits in support of the motion for a new trial and the conclusions that may be deducted from the statements of the prosecutrix, when considered in connection with the date of the birth of the child and the statements with respect to whether it was a full-term child or not. That such discrepancy is not a cause for granting a new trial when, as in this case, there is direct and positive evidence of the sexual act, is well and clearly illustrated in the two cases last above referred to.
*520Assuming, but not deciding, that the facts stated by the two physicians come within what is usually denominated as newly discovered evidence, yet those facts in one sense also clearly come within what is termed cumulative evidence. In no event, therefore, is this so-called newly discovered evidence “so conclusive in its character as to raise a reasonable presumption that the result of 4, 5 of a second trial would be different from the first,” which would have to be the case in order to authorize us to grant a new trial. (Armstrong v. Davis, 41 Cal. 499; Stoakes v. Monroe, 36 Cal. 388; Hayne, New Tr. and App., sec. 91.)
In view of the foregoing, we cannot interfere with the verdict of the jury, and especially not when the trial court has reviewed and approved the jury’s findings.
The judgment therefore is affirmed, with costs.
STKAUP, C. J. and McOAETY, J., concur.