The decision of the present case involves a further consideration of the pleadings in the much litigated action of the plaintiff against the principal in the bond now in suit, which has been four times before this court. Kellogg v. Kimball, 122 Mass. 163; 135 Mass. 125; 138 Mass. 441; 139 Mass. 296. It is now contended that the sureties on the bond given to dissolve the attachment in the original action were discharged by the allowance of the amendment to the declaration, adding a new count in place of the first and second counts in the original declaration. To have this effect, the amendment must be such as to let in some new demand or new cause of action, and not merely to vary the mode of stating the liability upon the same cause of action. Wood v. Denny, 7 Gray, 540. Smith v. Palmer, 6 Cush. 513. Cutter v. Richardson, 125 Mass. 72. The Pub. Sts. c. 167, § 85, provide that “the cause of action shall be deemed to be the same for which the action was brought, when it is made to appear to the court that it is the cause of action relied on by the plaintiff when the action was commenced, however the- same may be misdescribed.” The allowance of the amendment is conclusive evidence of the identity of the cause of action, as between the original parties; but *129not as to third persons who have no notice of the application for leave to amend. The- same cause of action may be set forth in a count in contract and a count in tort. Pub. Sts. c. 167, § 2, cl. 5. Mann v. Brewer, 7 Allen, 202.
In the present case, it is stated on the face of the amended count, that it “ is for the same cause of action as the first and second counts, and the third count, in said declaration, it being doubtful to which class said action belongs.” The allowance of the amendment shows that the judge who allowed it understood it to be for the same cause of action. The trial proceeded upon the same assumption, the case having been submitted to the jury, and a verdict having been taken upon the original third count and the amended count, as representing one cause of action. The defendants do not now contend, and we do not see, that the amended count was for a different cause of action from that set forth in the original third count; but they place their defence on the ground that the original declaration was insufficient, because it contained counts in contract and in tort, not averred to be for the same cause, which, therefore, could not legally be joined. There is no suggestion that the amended count introduced any new demand, or that it was anything else than a different mode of stating the original claim. The demurrer to the first two counts of the original declaration was sustained on the ground that they were improperly joined with the third count, merely because, as we understand from the defendant’s brief, there was no sufficient averment of identity in the cause of action. This defect was cured by inserting such an averment in the new count, and this does not have the effect to discharge the sureties. It is merely supplying a formal defect. This is the only question which we have to consider.
Judgment affirmed. .