Pathways to the abundant sulphur-containing carbon chain molecules, CCS and CCCS, are examined. The previously proposed ion/molecule mechanisms for the formation of these species appear satisfactory in the case of CCS, but arguments for the formation of CCCS via ion/molecule reactions rely on several assumptions which do not appear justified in the absence of sufficient experimental evidence. Alternative, radical/neutral pathways to CCS and CCCS (namely the reactions of C_2H with S, and with CS respectively) are proposed which can account for the observed high abundances of these species within TMC-1 and other objects. Thermochemical aspects of the various C_xS production mechanisms are assessed in the light of recent ab initio calculations on the chemical species concerned. Experimental study of the reaction of C_2H with CS is strongly urged.