delivered the opinion of the Court.

The appellant brought this suit for execution of a deed against the Heirs of her mother Angelina'Esbrí widow of Bauzá. She alleged that her predecessor died in December 1946; that the plaintiff lived with her and that the latter borrowed, in separate amounts, the sum of $2,730; that in order to pay said sum, Mrs. Esbrí agreed to convey to her two urban properties which are described in the complaint and to that effect gave instructions to notary Agustín E. Font to prepare the deed; that as soon as the contract was completed, the plaintiff took possession of the property and started to collect the rent from December 1946, precisely the. same month when the alleged vendor died without executing any document; that she requested the other heirs to comply with the contract of the deceased but since they refused, she prayed for judgment accordingly.

*422The defendants filed their answer in which they denied the essential allegations of the complaint.

The court a quo, after receiving extensive evidence, decided that Mrs. Esbri had never agreed with the plaintiff to give her the two properties in payment. This is the fundamental’ question in the present appeal. In support thereof, appellant assigns four errors. Three are directed against the weighing of the evidence and the remaining one consists in not having admitted the plaintiff’s testimony in connection with the alleged transactions between her and the deceased.

We shall commence the discussion by making a summary of 'the evidence introduced by the plaintiff.

The plaintiff lived with her mother until the latter’s death; the daughter had lent her mother different sums amounting to $2,730, and Mrs. Esbri, wishing to pay said debt, had agreed to transfer two lots located in the city of Ponce. To that effect the mother gave instructions to notary Agustín E. Font so that he would proceed to prepare the pertinent documents. The notary advised her to make a plan of the lots, as they had to be segregated from a larger property, which'she asked surveyor José Serra Gaztambide to do, which drawings were delivered to said notary, who did not prepare the documents because of Mrs. Esbri death.

Did the court a quo err in not believing this evidence? Attorney Font testified that Mrs. Esbri had called him to her house to ask him if she could sell some lots in spite of the mortgage thereon. Although at the beginning of his testimony he admitted that Mrs. Esbri had told him to prepare the deed of sale in favor of the plaintiff, later he rectified by denying that mention was made of preparing any deed for that purpose.

Serra Gaztambide, the surveyor who was commissioned to prepare the drawings, testified that he received an unsigned note in which he was asked to prepare them; that the nóte was delivered to him personally by Mrs. Esbri’s collector .who told him that it was sent by Doña Angelina; that *423as it was not signed, in order to verify its authenticity, he called Mrs. Esbrí, who confirmed over the phone the contents of the note but that he was not familiar with her voice.

Herminio Velázquez testified that he was Mrs. Esbri’s collector; that she had informed him of the agreement with the plaintiff; that Mrs. Esbrí dictated a note to him for Serra Gaztambide, which he personally took to the latter; that several days later, at the request of Mrs. Esbrí, he delivered to Serra Gaztambide the sum of $30, cost of the drawings, and on receiving the latter, he handed it to Attorney Font.

Rafael Rivera Esbrí testified that he was Mrs. Esbri’s nephew and manager and adviser of the plaintiff; that on a certain occasion while he was at his aunt’s home together with Attorney Font, she told the plaintiff that she had just given the data to said attorney so that he would prepare the deeds in her favor, but that the attorney had indicated to her the need of having a plan made, which she intended to order; that certain properties were conveyed by said deeds to the plaintiff as payment for a debt; that after Mrs. Es-bri’s death, he obtained a copy of the plan from Attorney Font and at the latter’s suggestion he chose Attorney Colón to bring the present suit.

Pedro Archevald and Josefa Colón, who were tenants of the houses located on the lots involved in this suit, testified that Mrs. Esbrí had told them before her death, that she had sold the lots to her daughter and asked them thereafter to pay the rent to the new owner.

Angel Prado, Mrs. Esbri’s son-in-law, as witness for the plaintiff, confined his testimony to identifying a letter that he had written to the plaintiff and which she presented and was admitted in evidence.1

*424According to defendants’ evidence, Mrs. Esbri knew how to write. Supposing it were true that she dictated to the collector the note she sent Serra Gaztambide, it does not explain the reason why, at least, she did not sign it. Did it not occur to her that an unsigned note could not be accepted as authentic? But it also appears from Angel Prado’s testimony, as witness for the defendants, that Mrs. Esbri was so deaf that in order to talk to her one had to shout at her ear and for that reason she had not been able to talk over the phone for years. Being so, how could the judge give credit to Serra Gaztambide’s testimony regarding his conversation with Mrs. Esbri, especially, if Serra did not know her voice? Does it not seem more reasonable that if she did *425not want or could not write, she would dictate the note to her own daughter, the plaintiff, who lived with her and managed her affairs? But there are other circumstances highly suspicious in the present case. Before filing this action a petition for judicial administration was filed by the plaintiff in the lower court. In this proceeding the liabilities and assets of the estate were reported. The alleged debt of $2,730 to the plaintiff did not appear among them. Likewise, it was not stated that the lots had been sold to her. On the contrary, they appeared as property belonging to the estate. It was some time after the petition for judicial administration was filed that Rafael Rivera Esbrí asked attorney Font to amend the petition so that said debt should *426appear. If as witness Rivera Esbri testified he was attorney-in-fact and adviser of the plaintiff and was present when his aunt told plaintiff that she had given instructions to Attorney Font to prepare the deeds on the lots, is it not inconsistent with said statement to request that the debt be included and not ask that it be stated in the judicial administration proceeding that the properties described in the complaint belonged to the plaintiff herein, by virtue of an agreement between mother and daughter? In Cintrón v. Cintrón 70 P.R.R. 734, which dealt with a simulated sale performed by a father in behalf of a daughter with prejudice to his other heirs, we said:

*427“We should not lose sight of the well-settled principle that transactions between close relatives that might prejudice other persons, should be examined with caution. Mackall v. Mackall, 135 U. S. 167.”

Under all these circumstances, we do not agree with appellant’s view that the trial judge erred in weighing the evidence. Far from that, his wise and sound conclusions in all respects reveal a careful and elaborate study of the case. Caballero v. González, 53 P.R.R. 513; Navarro v. Compañía Azucarera “El Ejemplo”, 53 P.R.R. 692, and Quock Ting v. United States, 140 U.S. 417, are cited by the appellant to maintain that since appellant’s evidence was not contradicted, the court was bound to give it full credit. Such is not the scope of -the doctrine prevailing in those cases. The rule is to the effect that the courts cannot disbelieve a witness whose testimony has not been contradicted unless there exists reasonable grounds for not believing it. In the present case, the trial court had reasons to doubt the veracity of the witnesses, and this being so, assuming that no evidence was introduced to contradict them, their own testimony discredited their evidence.

The fact that while witness José Serra Gaztambide was testifying, the judge stated that he did not wish to take part in the case because he could not believe that witness because of the manner he had testified in another case before him, is no reason for reversing the judgment for as we have seen, the witness’s testimony is so suspicious that even without the alleged prejudice, the judge would have been justified in not believing him. But furthermore, when the judge so stated at the trial, appellant’s attorney insisted on the judge’s intervention and vowed his absolute faith in the judge’s honorability. In such circumstances, we do not see how he can contradict himself when the outcome of the trial is adverse to him.

We shall now consider the remaining error.

When the plaintiff tried to testify on the transac*428tions had with her mother, the defendants relied on § 3 of the Act of March 10, 19042 to object to her testifying on the said point. The court sustained the objection and that is the ruling that appellant points out as an error. She invokes Boscio v. Vilá, 67 P.R.R. 567, and maintains that it reversed the principle established in Wilcox v. Axtmayer et al., 23 P.R.R. 319. There was no such reversal. In Wilcox, supra,- the complaint was filed against Henry Axtmayer and the heirs of his father Jacob Axtmayer, and it dealt with an action for attorney’s fees in which it was alleged that Jacob Axtmayer had promised to pay the plaintiff for professional services rendered to his son Henry. The same Section now invoked by the appellant was relied upon then and the opposition to Wilcox’ testimony on the agreement between him and the deceased Jacob Axtmayer with respect to the payment for professional services was sustained. The Wilcox case, supra, is clearly included within the provisions of § 3 copied in note 2, as it involved an action against the heirs of Jacob Axtmayer based on settlements had with the deceased. In Boscio v. Vilá, supra, the facts were different from Wilcox, supra, for it involved an action brought by a stepmother against her stepdaughter to recover the widow’s share and her share of conjugal property in a house that was claimed to have been conveyed to the defendant by the plaintiff and her husband under a simulated sale. When the plaintiff tried to testify on the agreement reached between her and her husband with the defendant, the latter objected, citing the afore-mentioned § 3. The court sustained the objection and since the plaintiff stated that she did not have *429any other evidence to support her case, it dismissed the complaint. An appeal was taken and this Court stated that if the plaintiff eliminated her claim to the widow’s share, the afore-mentioned. § 3 would not be applicable then, inasmuch as the plaintiff would then limit herself to claim her share in the community property and in such case she would be claiming that to which she was entitled by her own right, that is, not as her husband’s heir, against a party who was not sued as her father’s heir, but for the alleged title of ownership which she held by virtue of the simulated sale. As to the widow’s share, Wilcox, supra, was followed.

In the present case, the situation is the same as in Wilcox v. Axtmayer, supra. The plaintiff does not bring her action as her mother’s heir, but by virtue of the title she claims to have acquired through the alleged contract with her mother and the action is directed, as in Wilcox, against her mother’s heirs. So that it deals with an action brought against the heirs of the person with whom the alleged agreement was reached. This being so, the plaintiff’s testimony in relation to the transaction had with Angelina Esbri falls under the prohibitions of the afore-mentioned § 3 and the lower court did not err in excluding it.

The judgment will be affirmed.