This appeal is from an order denying plaintiff’s motion or application for leave to file a supplemental complaint in an action to foreclose a chattel mortgage, given by defendant to secure the payment of a promissory note which had not matured, according to its terms, at the time the suit was instituted. By the terms of the mortgage which was made a part of the original complaint, the mortgagees were expressly authorized to foreclose at *165any time they deemed themselves insecure, or in case the mortgaged property depreciated in value; and it was alleged that the property described in the mortgage had greatly depreciated in value, and that plaintiffs, deeming themselves insecure, had elected to foreclose said mortgage, and apply the proceeds of the sale to the payment of the indebtedness secured thereby. It appears incidentally that defendant answered, but the nature of his defense is not disclosed by the record. The time for which the note was to run having expired during the time the action was pending, the nonpayment thereof at maturity was alleged in the supplemental complaint, which contained a prayer for the same relief demanded in plaintiff’s original complaint.
Section 4942 of the Compiled Laws provides that “the plaintiff * * * may be allowed on motion to make a supplemental complaint, * * * alleging facts material to the case occurring after the former complaint * * * was made.” And thus an exception usually recognized in Code states is made to the rule that a party must rely upon his cause of action as it existed at the commencement of the suit. While we regard the statute directory, as the word “may” was evidently not employed as a mandatory expression, we ai’e inclined to the belief that an application to file a supplemental complaint should ordinarily be granted when it relates to the same cause of action, and the matter contained therein appears to be material to the plaintiff, and when it is clear that a court, by an abuse of its discretion, has materially prejudiced the rights of the party by a refusal to grant leave to file a supplemental complaint, the action of such court will be reviewed on appeal. Under the allegations of the complaint based upon the stipulation in the mortgage, plaintiffs would be entitled to all the relief demanded in their supplemental pleading, upon proof of a material depreciation in the value of the property occurring since the execution of the mortgage, or of other facts sufficient to justify the mortgagees in deeming themselves insecure. Humpfner v. Osborne, 2 S. D. 310, 50 N. W. 88; Allen v. Vose, 34 Hun. 57; Botsford v. Murphy, 47 Mich. 536, 537, 11 N. W. 375, 376; Roy v. Groings, 96 Ill. 361.
*166In tbe absence of an answer traversing tbe averments upon wbicb plaintiffs rely, and with nothing before us to indicate that defendant was in a position to resist a foreclosure and sale of tbe property in'satisfaction of tbe indebtedness secured by tbe mortgage, we cannot assume that tbe action of tbe court in denying tbe motion to file a supplemental complaint was prejudicial to plaintiffs, or tbat tbe court abused its discretion in making tbe order from wbicb tbe appeal is taken. It must be presumed tbat tbe trial court, upon an examination of tbe answer of tbe defendant, wbicb is not before us, and upon due deliberation, exercised a discretionary power, wbicb cannot be reviewed and reversed upon' tbe record presented; and tbe order appealed from is therefore affirmed.