Behavior of the delayed formation of latent image specks in a vacuum on sulfur+gold-sensitized emulsions with cubic and octahedral grains was studied. The fraction of developed grains P increased by storing in a vacuum after exposure. In the cubic grain emulsion P exhibited an exponential one-step increase. On the octahedral grain emulsion P indicated a two-step increase. The first step was exponential and the second step was S-shaped. The delayed formation diminished with the increase of sensitization level and disappeared completely at the highest level. Latent subimage specks in the sulfur+gold-sensitized emulsion were developable by absorbing one photon, but not by adding one silver atom in the delayed formation process. The mechanism of the two-step increase in developability is also discussed.