Glass temperatures are given for copolymers containing methyl methacrylate and from 0 to 100% of each of the dimethacrylates of ethylene glycol (EGDMA), decamethylene glycol (DGDMA), and 2‐ethyl‐2‐butylpropanediol‐1,3 (2‐E‐2‐B‐PDMA), and for copolymers containing from 0 to 17 mole per cent of the dimethacrylate of 2,2‐dimethylpropanediol (2‐2‐D‐PDMA). The relation between T_g and the mole fraction of dimethacrylate in the copolymers is complex, maxima being observed for the DGDMA and 2‐E‐2‐B‐PDMA copolymers. This unexpected behavior is interpreted on the basis that the introduction of crosslinkages by copolymerization of a vinyl with a divinyl monomer affects T_g by concomitant changes in the average copolymer composition (“copolymer effect”) and the degree of crosslinking (“crosslinking effect”). The copolymer effect is obtained separately for the MMA‐EGDMA copolymers from the observed T_g‐composition relation for copolymers of MMA with ethylene glycol monomethacrylate, monoisobutyrate. The crosslinking effect per se is then calculated on the basis of the assumption that the copolymer and crosslinking effects are independent and additive. For the EGDMA copolymers, it is found that the effect of crosslinking alone causes T_g to increase linearly with an increase in the number (ρ) of crosslinks per gram of polymer, and that the proportionality constant is of the same order of magnitude as that observed in the preceding paper for the styrene‐divinylbenzene copolymers. This observed T_g‐ρ relation is in semiquantitative agreement with the equations of the preceding paper, and lends support to the concept of additivity and independence of the copolymer and crosslinking effects upon which the observations are based. The results on the MMA‐EGDMA copolymers, together with the less extensive data on the other copolymers, indicate that the magnitude of the increase in T_g for each crosslink introduced is essentially independent of the structure of the crosslinker.