22 THE LOWER FUNGI— PHYCOMYCETES 



higher members of any one group show relationship with the 

 lower members of the groups above. He felt that any attempt 

 to merge the two series would necessarily result in the dismember- 

 ment of both. Since the physiological processes of organisms 

 possessing chlorophyll are very different from those of forms in 

 which it is lacking, it seemed highly unlikely to him that the 

 change from one type of metabolism to the other had occurred 

 at a number of different points along the algal line. He con- 

 cluded finally that the algae and fungi probably arose as separate 

 groups very early from unicellular chlorophyll bearing and non- 

 chlorophyll bearing organisms respectively, and have subse- 

 quently evolved along more or less parallel lines. The rather 

 constant environmental conditions characterizing the aquatic 

 habit has been offered in explanation of the development of 

 similar structures in the two series. 



The two opposing points of view have persisted with minor 

 alterations to the present day. In most standard taxonomic 

 works the ideas of de Bary have prevailed, and the algae and fungi 

 are treated as separate groups. In America, the teachings of 

 Sachs were elaborated by one of his students, Charles Bessey 

 (1907; 1914), at the University of Nebraska, and the interpolation 

 of the fungi in the algal series constitutes an outstanding feature 

 of the system of classification used by the Bessey school of 

 botanists (Ernst Bessey 1913). Certain other students of the 

 cryptogams who agree in regarding the fungi as degenerate 

 algae are content for convenience sake to have the two groups 

 treated taxonomically as distinct. 



In recent years de Bary's suggestion that the two series have 

 evolved in parallel has been championed by various students 

 (Vuillemin, 1912). In America this point of view was given 

 prominence by Atkinson (1909; 1915). He presents the evidence 

 indicating that the fungi have in fact no connection with the 

 algal line, but instead have been derived from primitive colorless 

 organisms below the level of the existing Chytridiales. He 

 emphasizes the fact that in a number of points of morphology 

 and behavior the lower fungi resemble the higher, and differ 

 from the algae. He contrasts the zoospores of the fungi with 

 those of the algae, finds in the Chytridiales the origin of the 

 phenomena of diplanetism of swarmspores and proliferation of 

 sporangia characteristic of some of the Saprolegniales, sees in 

 certain of the Chytridiales and Ancylistales the origin of the 



