The author deplores the pernicious effect of Schwendener's plan of the arrangement of lichens. As a result lichens received only casual mention in an appendix to the different groups of lichens. Lichenologists (systematic) in general have strongly opposed Schwendener's plan of classification. Although Reinke has always sympathized with these lichenologists, yet he regrets very much that they should have made their special attack upon Schwendener's theory of the dual nature of lichens.
The following is a brief summary of the leading items discussed in this paper : I. The true relation of fungus and alga in the lichen-thallus was first pointed out by Reinke.
2. The term Consort/ism antedates the term Symbiosis.
3. Schwendener's (De Bary's) theory of the dual nature of lichens is fully accepted.
4. Most of the algal types occurring in lichens have been specifically determined. The fungal types no longer exist (at least in most cases) and can therefore not be determined.
5. A lichen is a phylogenetically derived morphological unit.
6. Lichens form groups of natural series phylogenetically de rived from distinct prototypes. Lichens have, therefore a poly phyletic origin.
7. Lichens differ from the fungi morphologically as well as physiologically.
The following are the general conclusions at which Reinke arrives: I. Although fully accepting Schwendener's theory, lichens are phylogenetically, morphologically and physiologically wholly dis tinct from fungi, and it is therefore inconsistent to arrange them under fungi.
2. Lichens form a natural group coequal in systematic impor tance with fungi and algae.
Since Reinke has written this paper Schwendener in a per sonal interview with E. L. Gregory * stated that he had no objec tion to the proposed plan of classification. Tubeuf, j as well as other recent authors, expresses the opinion that the lichen is an autonomous structure, a morphological unit. There are also strong objections, such as those cited by Lindau. 4