As the pointed podetia are the more primitive, Sättler points out that they may reappear as retrogressive structures, and have so appeared in the “pyxidata” group in such species as _Cl. fimbriata_. He refers to Wainio’s statement that the abortion of the apothecium being a retrogressive anomaly, while scyphus formation is an evolutionary advance, the scyphiferous species present the singular case, “that a progressive transmutation induced by a retrogressive anomaly has become constant.” His third group includes those forms that grow in crowded tufts or swards such as _Cl. rangiferina_, _Cl. furcata_, _Cl. gracilis_, etc. They originate, as did the pyxidata group, in some _Floerkeana_-like form, but in the “rangiferina” group instead of cup-formation there is extensive branching. In the closely packed phalanx of branches water is retained as in similar growths of mosses, and moist conditions necessary for fertilization are thus secured as efficiently as by the water-holding scyphus. Sättler in his argument has passed over many important points. Above all he ignores the fact that whatever may have been the original nature and function of the podetium, it has now become a thalline structure and provides for the vegetative life of the plant, and that it is in its thalline condition that the many variations have been formed; the scyphus is not, as he contends, a new thallus, it is only an extension of thalline characters already acquired. 8. PILOPHORUS, STEREOCAULON AND ARGOPSIS. These closely related genera are classified with _Cladonia_ as they share with it the twofold thallus and the lecideine apothecia. The origin of the podetium being different they may be held to constitute a phylum apart, which has however taken origin also from some _Biatora_ form. The primary thallus is crustaceous or minutely squamulose and the podetia of _Pilophorus_, which are short and unbranched (or very sparingly branched), are beset with thalline granules. The podetia of _Stereocaulon_ and _Argopsis_ are copiously branched and are more or less thickly covered with minute variously divided leaflets. Cephalodia containing blue-green algae occur on the podetia of these latter genera; in _Pilophorus_ they are intermixed with the primary thallus. The tissue systems are less advanced in these genera than in _Cladonia_: there is no cortex present either in _Pilophorus_ or in _Argopsis_ or in some species of _Stereocaulon_, though in others a gelatinous amorphous layer covers the podetia and also the stalk leaflets. The stalks are filled with loose hyphae in the centre.