Abstract 1. 1. The incorporation of radioactivity from [ 14C] glucose, [2 −14C] acetate and [1:4 −14C 2] succinate into the soluble intermediates of homogenates of Pomatias elegans, Helix pomatia, Cepaea nemoralis and Cepaea hortensis has been studied. 2. 2. Radiocarbon from the labelled substrates was incorporated into substances known to be involved in glycosis, the tricarboxylic acid cycle, transamination and synthetic reactions. 3. 3. Some implications of these results are discussed.