delivered the opinion of the court.
The appellants assign numerous errors upon the rulings of the court below, which, when summarized present for our consideration the following questions :
First. Can a mortgagee maintain an action at law, in his own name, to recover his mortgage debt against a grantee who accepts a conveyance of the mortgaged premises containing an agreement to assume and pay the same ?
Second. Can appellee, as assignee and legal owner of the secured notes, maintain this action ?
Third. Can the grantor release the grantee from the obligations incurred by the assumption agreement, without the consent of the beneficiary? In other words, was the attempted rélease by Wellington effectual to relieve appellants from their liability upon their assumption agreement to Tanquary & Gibson?
Fourth. Did the conveyance of the property to Linn, in pursuance of the alleged agreement of release, change the relations of the parties, and make Wellington the principal debtor, and the appellants merely sureties, so that the discharge of the attachment on his property, or the extension of the time of payment of the notes, operated to discharge them from liability ?
Fifth. Was the original contract between Wellington and appellants admissible under the issues made by the pleadings, to contradict the assumption agreement contained in the deed?
Upon the first proposition there is a diversity of opinion among the courts of last resort in this country, growing out of the particular view that each tribunal has taken as to the ground of the liability of the grantee who assumes the payment of a mortgage upon the property conveyed to him; some holding that his liability depends upon the equitable doctrine of subrogation, and that the obligation he assumes can be enforced only in an equitable proceeding; while others hold that it arises out of contract, and constitutes a legal *26liability, enforceable in an action at law. The latter is not only the better and more generally accepted view, but is the one that prevails in this jurisdiction. Green v. Morrison, 5 Colo. 18; Skinner v. Marker, 23 Colo. 333; Woods Inv. Co. v. Palmer, 45 Pac. Rep. 237, 8 Colo. Ct. App. 132; Burbank v. Roots, 4 Colo. Ct. App. 197 ; Stuyvesant v. Western Mortgage Co., 22 Colo. 28. Mr. Pomeroy, in discussing the rationale of the grantee’s liability, in Ms work on Equity Jurisprudence, uses the following language:
“ The ground of grantee’s liability adopted by the courts of a large majority of the states, is that of contract. It is an application of the general doctrine, so widely prevailing in tMs country that it may properly be called an American doctrine—where A. makes a promise directly to B., for the benefit of C., upon a consideration moving alone from B., G. being the party beneficially interested may treat the promise as though made to himself, and may maintain an action at law upon it in his own name against A. the promisor. According to this generally accepted view, the liability of the grantee, who thus assumes the payment of an outstanding mortgage, does not depend upon any exte:rsion of the equitable doctrine concerning subrogation; it is strictly legal, arising out of a contract binding at law; the mortgagee, instead of enforcing the liability by a suit in equity for a foreclosure, may maintain an action at law against the grantee upon his promise, and recover a personal judgment for the whole'mortgage debt.” Pomeroy’s Eq. Jur. Vol. 3, §1207.
Among the adjudicated cases announcing this rule are: Burr v. Beers, 24 N. Y. 178; Thorp v. Keokuk Coal Co., 48 N. Y. 253; Dean v. Walker, 107 Ill. 540; Bay v. Williams, 112 Ill. 91; Schmucker v. Sibert, 18 Kan. 104; Urquhart v. Brayton, 12 R. I. 169; Ross v. Kennison, 38 Ia. 396; Rogers v. Gosnell, 58 Mo. 589; Merriman v. Moore, 90 Pa. St. 78; Follansbee v. Johnson, 28 Minn. 311; Bassett v. Hughes, 43 Wis. 319; Bliss on Code Pleading, sec. 128.
But it is strenuously insisted by counsel for appellants that a distinction should be made where the assumption *27agreement is contained in a deed, as in this case, upon the theory that the assumption clause must be treated as a covenant, and that an action on a covenant will only lie in the name of the covenantee. But this technical rule of the common law does not prevail in states that have adopted the reform procedure. Under our code the action must be prosecuted in the name of the real party in interest; and certainly the beneficiary, or person for whose benefit the promise is made, is the real party in interest, whether the promise is evidenced by a simple contract, or one under seal. Pomeroy on Remedies & Remedial Rights, sec. 189; Bliss on Code Pleading, sec. 58; McDowell v. Laev, 35 Wis. 171; Bassett v. Hughes, supra; Fitzgerald v. Barker, 70 Mo. 685; Emmitt v. Brophy, 42 Ohio St. 82; Van Schaick v. R. R. Co., 38 N. Y. 346; Lawrence v. Fox, 20 N. Y. 268.
In these cases, and many others that might be cited, the old rule that no one but a covenantee could sue on a covenant is distinctly repudiated; and it is held that a grantee who accepts a deed poll containing an assumption agreement to pay a mortgage, becomes personally liable to the mortgagee, who may maintain a suit in his own name upon such covenant or agreement, for the mortgage debt.
We think, therefore, the first question must be answered in the affirmative; and that the assignment and transfer of the notes to appellee, vesting the entire legal title thereto in him, constituted him, as such legal owner, the real party in interest within the meaning of the code, and entitled him to maintain this action. This seems to be the settled doctrine in most of the states. Pom. on Rem. & Rem. Rights, secs. 128, 132; Bliss on Code Pleadings, sec. 51 and cases cited; and is expressly recognized in Bassett v. Inman, 7 Colo. 270.
In the view we take of the nature of appellants’ liability upon the assumption agreement contained in their deed, the answer to the third question presented is easy of solution. It is obvious that if, as we have seen, the assumption clause in the deed imposed an obligation upon appellants primarily *28for the benefit of Tanquary & Gibson, and not for the indemnity of their grantor, that by accepting the deed, they became effectually bound by such obligation, and an immediate right to enforce it vested in the beneficiaries; which right could not be divested without their consent.
Mr. Jones, treating this subject in Ms Work on Mortgages, Yol. 1, sec. 764, says:
“ The result of the latest cases upon tMs subject is, that, where the conveyance is absolute to the grantee, Ms assumption of an existing mortgage creates against him an absolute obligation for its payment, and that a release of this obligation cannot be made by the grantor without the assent of the mortgagee. The acceptance on the part of the mortgagee of the benefit of the assumption is a legal presumption, in the absence of proof, of his actual dissent.”
And m Devlin on Deeds^sec. 1093, it is said:
“Two opposite views prevail as to the power of the grant- or to deprive a mortgagee of the stipulation made by a grantee to assume a mortgage. Where the covenant is considered one of indemnity only, of which the mortgagee may take advantage by a species of equitable subrogation, the parties to the covenant may at any time before a bill for foreclosure is filed, discharge the liability by a reconveyance, and as there is then no longer any contract of indemnity, there can be no right to which the mortgagee can be subrogated. And this may be done under tMs view by a simple release. But on the other hand, in other courts, the promise is regarded as irrevocable, and it is held that where the d_eed to the grantee is absolute, he incurs an absolute obligation for its payment by assuming it, and that without the consent of the mortgagee, the grantor cannot release this obligation.”
See also Bassett v. Hughes, supra ; Bay v. Williams, supra ; Douglass v. Wells, 18 Hun, 88; Gifford v. Corrigan, 117 N. Y. 357; Rogers v. Gosnell, supra ; Ranney v. McMullen, 5 Abbott’s New Cases, 246.
We think, therefore, it necessarily and logically follows *29that the alleged release by Wellington, of appellants, whatever its effect may be as between themselves, was wholly ineffectual to relieve them of their liability to Tanquary & Gibson. It is, however, insisted that by the conveyance made in pursuance of the agreement with Wellington, the relation of the parties was changed, and that thereby Wellington became the principal debtor, and the appellants merely sureties; and that by their subsequent dealings with Wellington, Tanquary & Gibson released appellants from all liability upon the notes.
We think this claim is untenable. There is no averment in the answer to the effect that, in consideration of such release, Wellington made any new promise to pay the notes, or agreed to indemnify appellants against the liability they had assumed. But it does appear, by the terms of the deed, that Linn assumed their payment, so that any agreement which Tanquary & Gibson might have made with Wellington, was an agréement with him as surety merely, and in no way affected the liability of appellants, who still remained liable to Tanquary & Gibson, as principal debtors.
Upon the question of the admissibility of the original contract between Wellington and appellants, to contradict the assumption clause in the deed, we are cited to the cases of Elliott v. Sackett, 108 U. S. 182; Drury v. Hayden, 111 U. S. 223. Under the doctrine of these cases, (in which we fully concur) a party accepting a deed in which an assumption clause has been inserted contrary to the intention, and without the knowledge, of the parties, by fraud or mistake, and without actual knowledge of such clause being in the deed, may upon proof of such mistake or fraud, be relieved therefrom. But such a defense, to be available, must be pleaded. In the case at bar there is no suggestion in the answer that the assumption clause contained in the deed from Wellington to appellants was inserted by fraud or mistake; or that appellants accepted the deed without knowledge that it contained such a clause. In those portions of the answer setting *30out the release relied on, there is no intimation that the assumption'clause in the deed was wrongfully inserted; but, on the other hand, it is treated as a binding obligation upon appellants, and exemption therefrom is claimed solely on the ground of the payment of a valuable consideration. The only averment contained in the answer that is relied on as presenting such defense is the third general defense, wherein defendants deny that they assumed or agreed to pay the notes. It is too well settled to admit of discussion, that fraud or mistake, to be available, must be specificahy averred.
It is alleged in the complaint that the deed in question was delivered to defendants, and by them accepted, and that they caused said deed to be filed for record in the office of the county clerk and recorder of Arapahoe county. This allegation is not here controverted in the answer. In Muhlig v. Fiske, 181 Mass. 110, it is said:
“If the deed of conveyance from the plaintiff to the defendant was delivered by the grantor and accepted by the grantee, the latter thereby assumed the duty of performing according to its terms the promise therein expressed to be made by lfim. » * * The defendant, having, by the delivery Avhich the jury have found, accepted the deed of conveyance and thereby obtained the estate Avhich he afterwards conveyed to a third person, and so made himself liable to the burden wlfich by the terms of the deed he had assumed, could not (no fraud in the execution or delivery of the deed being suggested) impair the legal effect of Ms own act by oral evidence that he had never agreed to assume and pay the mortgage, nor authorized nor knew of the insertion of such an agreement in the deed. Such eAridence, except so far as it tended to show that there had been no delivery of the deed, was therefore rightly excluded, independently of any question of pleading.”
We think, under the pleadings in this case, the evidence sought to be introduced for the purpose of contradicting the assumption clause in the deed, was properly excluded.
*31Upon a careful consideration of the entire record, we think the court below properly directed the jury to render a verdict in favor of plaintiff, and the judgment is accordingly affirmed.