In 1930 the author (Graham-Smith, 1930) showed that of spores of B. anthracis inoculated on 7 July 1907, on to dry, sterile pieces of canvas, measuring about 0·5 × 0·5 in., which were kept in a Petri dish in a cupboard with a glass door in the laboratory and therefore exposed to diffuse daylight at room temperature in a dry atmosphere, large numbers were capable of germinating in ordinary laboratory media after 10 years and progressively smaller numbers after 17 and 20 years. Very few germinated after 22 years and none after 22½ years.