Planaria
We need a reference for the flatworm claim. I've taught the flatworm story for years. The 'memory' is just stress hormones (generated when the 'donor' flatworm has to learn a stressful task) which affect the rate at which regenerated (or cannibal) flatworms learn a task. Please take a look at Frank, Stein & Rosen (1970) 169, 339-402. It is a fabulous debunking of 'chemical memory'.