The evidence furnished by the defendant’s testimony was sufficient to sustain the judgment that was rendered. According to the plaintiffs’ petition the defendant “ bound, obligated himself, and promised to pay ” the plaintiffs, on demand, what the goods were reasonably worth. The evidence of what that value was is shown by agreement between the contracting parties at the times of the respective sales and delivery of the goods, which the defendant testified was the several sums of money charged in the itemized account sued on; and as between the parties to the sale such evidence must be deemed conclusive. Such a transaction is, it is true, a contract for sale of the goods at a stipulated, fixed price, yet it is not incompatible with the cause of action as set forth in the petition. Clearly the plaintiffs could not, under their allegation's, recover as the reasonable value of the goods, an amount in excess of that which had been agreed on as their value, but they may recover the particular sum or sums thus agreed on, or any less sum.
The cause of action set forth being for the value of the goods, that value may be shown by evidence which establishes the agreement of the parties ascertaining at the time of the sale what that value was. This view does not derogate, we conceive, from the rule of law so firmly established in numerous cases decided by our supreme court (Mims v. Mitchell, 1 Tex., 443; McGreal v. Wilson, 9 Tex., 426; Hunt v. Wright, 13 Tex., 549; Gammage v. Alexander, 14 Tex., 414), to the effect that the allegata and probata must correspond and agree, and that no verdict or judgment can be *575sustained unless there has been an averment to let in the evidence on which the same is based.
A distinction must be recognized, xve think, betxveen this case and that xvhere the plaintiff relies for recovery on allegations of a special contract as to the terms and the price of the goods, and attempts to support the action by proof of the value of the goods xvithout reference to the special contract; or, as in McG-real v. Wilson, supra, where the petitioner alleged a contract to pay a specific amount for services to be rendered, and sought to maintain the suit by proof as to the reasonable value of the services. In such cases as those the departure from the action sued on is apparent, and the evidence offered in such cases tends to and generally would establish a basis of recovery variant from the contract of the parties, and consequently a liability would be fixed thereby wholly different from that xvhich the plaintiff’s petition claimed against the defendant. But in the case before u$, the plaintiffs’ cause of action virtually asserts that the goods sold were of the values specified in the items respectively of the account, and the evidence shows that the contracting parties agreed at the time of the sales thereof, that the goods were of the xmlues claimed by the petition. The testimony of the defendant establishing the value of the goods as agreed on xvas offered xvithout objection, and it may be reasonably inferred was introduced at his oxvn instance, and it thus being before the court xvas the proper subject of consideration. It tended to and was indeed amply sufficient to sustain the plaintiffs’ cause of action.
It is urged that there was no evidence of a demand. When an obligation to pay is complete a cause of action at once arises, and no formal demand is necessary. Watson v. Walker, 23 N. H., 471; O’Conner v. Dingley, 26 Cal., 11.
The fair and reasonable construction of the contract of the sales of the goods, as set forth in the petition, is that the prices for xvhich the goods xvere sold were due and payable at the time of delivery, or at such time thereafter as the plaintiffs should elect to demand payment, and not that the sales xvere made on an indefinite credit, the limit of which was to be ascertained and determined by a formal demand for payment. Therefore no demand before suit was necessary.
Under the view we have taken of this case it is not essential to consider any other of the assigned errors than such as have been discussed in this opinion, and we conclude that the judgment ought to be affirmed.
Affirmed.
[Opinion adopted January 15, 1884.]