1. The ontogeny of the podetium and the apothecium in Cladonia ecmocyna Nyl. is investigated morphologically and anatomically. The podetia are formed by generative tissue. Sexual organs and apothecia are only formed at the top of grown podetia. The development is the same as in Cladonia chlorophaea, described by Jahns 1969. 2. The phyllocladia are formed by growth of the algal layer of the podetium. In the process a piece of the cortex is torn free at the basal side of the primordium of the phyllocladium and bent upwards. 3. Phyllocladia are also formed at the margin of old cups. The phyllocladia of old, rotten podetia can assume the function of the thallus horizontalis. New podetia emerge from them. 4. The tissue of the apothecium is not fundamentally determinant. It was observed that on the disc of an apothecium a phyllocladium had been formed by the subhymenial tissue. On this phyllocladium a pycnidium was found.