The adsorption parameters (alpha) established for the monosubstituted acetylenic liquids in this investigation are consistent with expectation based on analogies with the log alpha(f) = log alpha(i) - D-s(N-f - N-i) relationships reported earlier far the many homologous series of liquids ZR, in which Z is a functional group having strong affinity for the pendent phenyl group of polystyrene and R is an alkyl substituent that is varied systematically. The order of relative Z-affinities, based on alpha for the respective ZCH(2)CH(3) molecules, confirm that the nature of Z is the major factor that affects alpha and that electronic and steric contributions from R are modifying effects, which are reflected in D-3. Comparisons of the results observed for HC=C(CH2)(n)Z' liquids with those for HC=C(CH2)(n)H and with analogous pairs of Z(CH2)(n)Z' series confirm that Z' at the other end of the polymethylene chain can have a moderate positive effect or a marked negative effect on alpha, depending on whether the mode of adsorption to pendent phenyl groups is mono- or bidentate. This study also confirms that a sharp reversal in the roles played by the molecules participating in the adsorption process occurs when all of the hydrogen atoms covalently bonded to the center of unsaturation are replaced by alkyl substituents.