Dictyostelium discoideum fruiting bodies observed by scanning electron microscopy

The fruiting bodies of Dictyostelium discoideum, fixed in a vapor of 25% glutaraldehyde, were observed by scanning electron microscopy. The surface of the basal disk had rootlike ripples, sometimes with concentric rings of riblike striations at its periphery. The surface of the stalk had pleated and twisted ridges along its entire length, but no lateral projections. The spores were randomly orientated and had a crinkled surface. The surface of the lower part of the papilla had flattened ridges running horizontally. A slime coat remained in the region of transition between the stalk and sporangium, but not on the spores.