The sonic disruption of spores of Bacillus cereus gives multi-hit kinetics. The first hit destroys the exosporium, which protects the spore body from destruction; the second hit destroys the spore body. Spores which have been stripped of their exosporia are still viable and heat resistant. From the rate of release during sonic treatment it appears that alanine racemase, adenosine deaminase and hexosamine are located in the exosporium while ribosidase is in the spore body. The rate of release of dipicolinic acid does not identify its location.