delivered the opinion of the court.

This was a suit begun in the Municipal Court of San *810Germán and purported to be (1) for the execution of a deed for the sale of land; (2) for the annulment of an alleged simulated sale of land and the record thereof; (3) for the annulment of a mortgage and record thereof. The suit was brought by one who alleged himself to be the attorney in fact of another, but without setting forth the power of attorney in the complaint or the essential words of said power which would establish the character of said complaint, A demurrer was filed to' the complaint while the case was pending in the municipal court. On appeal to the district court judgment was rendered for the defendants on said demurrer.

The appeal must be dismissed for failure to comply with Buies 42 and 43 of this court. There is no assignment of errors in the brief. We have considered these rules in various cases. Gordils v. Sucs. of Frontera, Ltd., et al. 21 P. R. R. 218; Méndez v. Martínez, 26 P. R. R. 89; Goble & Jiménez v. Truyol & Co., 27 P. R. R. 363, and Royal Bank of Canada v. McCormick & Co. et al., 27 P. R. R. 383. See also 3 C. J. 1483,. 1495, pp. 1343 et seq.

We have, of course, a discretion if we find a fundamental error, but we do not feel bound to scan closely a rambling complaint and an incomplete brief to find such fundamental error. Furthermore, as we have seen, the power of attorney is not before us, nor any adequate reference to its contents and we are inclined to believe therefore that the complainant showed no cause of action.

All that the said complaint states is that the appellant is the attorney in fact, which seems to be a legal conclusion. A person may be an attorney in fact for various purposes and still not be authorized to file a suit in substitution of another. A defect of this nature is not one of incapacity in the parties but goes to the foundation of the action. 31 Cyc. 296. .

Likewise we are in some doubt whether an attorney in *811fact would have a cause of action in Ms own name, but we need not specifically decide tbe question.

Tbe appeal must be

Dismissed.