Title XXXV CIVIL PROCEDURE AND LIMITATIONS Chapter 509 Effective - 28 Aug 1943 509.440. When claim may be presented as counterclaim by supplemental pleading. — A claim which either matured or was acquired by the pleader after serving his pleading may, with the permission of the court, be presented as a counterclaim by supplemental pleading. -------- (L. 1943 p. 353 § 75)
Missouri Legal Code