Fig. 1. Small, undifferentiated stroma of Venturia inaequalis between the host cell wall and cuticular membrane. Ap, appressorium; CM, cuticular membrane; EC, epidermal cell; HCW, host cell wall; MS, mucilaginous substance; St, stroma (83). Reprinted by permission. Fig. 2. "The Supper at Emmaus" by Michelangelo M. da Caravaggio, painted c. 1600. Enlargement of the basket of fruit shows clearly several scab lesions on the apples. Published by kind permission of the Trustees of the National Gallery, London.