When a jury is required by law in the trial of causes, civil and criminal, in a county court, such jury shall consist of six persons. All criminal cases wherein the punishment does not exceed a fine of one hundred dollars or imprisonment for thirty days shall be tried before the county judge without a jury, unless a trial by jury is demanded by the accused. Such cases wherein a trial by jury is not so demanded shall be carried to the foot of the calendar, to await trial by the county judge after the jury cases for the term have been disposed of.