Cyanide gland, expertly dissected from Pachydesmus crassicutis by Tim McCoy. The large balloon shaped reservoir on the left stores the stable precursor mandelonitrile, which is squeezed into the thickened, oval-shaped reaction chamber on the right. In the reaction chamber, mandelonitrile reacts with an enzyme to produce cyanide and benzaldehyde. The noxious cocktail is finally exuded from the “ozopore” opening to the environment (tubular projection shown on the right). This structure is located internally with the precursor reservoir facing mediad (towards the heart & nerve cord) and reaction chamber oriented laterad (towards the face of a marauding predator).
Reference: Eisner, T., H.E. Eisner, J.J. Hurst, F.C. Kafatos, J. Meinwald. 1963. Cyanogenic glandular apparatus of a millipede. Science, 139, 1218-1220.