509.060. The plaintiff in his petition or in a reply settingforth a counterclaim and the defendant in an answer setting fortha counterclaim may join either as independent or as alternateclaims as many claims either legal or equitable or both as he mayhave against an opposing party. There may be a like joinder ofclaims where there are multiple parties if the requirements ofsections 507.030, 507.040 and 507.060, RSMo, are satisfied.There may be a like joinder of cross-claims or third-party claimsif the requirements of section 509.460 and section 507.080, RSMo,respectively, are satisfied.
(L. 1943 p. 353 ยง 37)