The contentions made in appellant's brief are that mandamus was not the proper remedy and that the population of McDonald County, as determined by the census of 1930, must be taken as the basis for computing Perkins' salary regardless of the fact that the statute prescribes another basis, the total number of votes cast in the presidential election of 1928. No declarations of law were asked or given. No question of the constitutional authority of the Legislature to adopt that basis, nor question of the constitutionality of the statute on any other ground was raised below and therefore none can be considered here. It appears, however, from some of the argument in appellant's brief they seem to contend that the Legislature has no authority to make anything the basis for fixing salaries of county officers except the population of the county as determined by the United States census. Section 12 of Article 9 of the Constitution is cited. It provides that "the General Assembly shall, by a law uniform in its operation, provide for and regulate the fees of all county officers, and for this purpose may classify the counties by population." Although the question is not raised so that it would be before us for decision, here, we deem it proper to call attention to the fact that this court has already decided against the contention that this provision requires the Legislature to make population the basis for fixing salaries of county officers. [State ex rel. O'Connor v. Riedel, supra; State ex rel. Chaney v. Grinstead, 314 Mo. 55, 282 S.W. 815; Greene County v. Lydy,263 Mo. 77, 172 S.W. 376, Ann. Cas. 1917C, 274.]