234 A CENTURY OF PROGRESS IN THE NATURAL SCIENCES 



But with the opening of the eighteenth century there were a few students who 

 gave great care and much time to the study and naming of fungi. Chief among 

 these were Dillenius (1719) and Micheli (1729). These lived respectively from 

 1687 to 1747 and from 1679 to 1737. Linnaeus (1753) brought together in his 

 twenty-fourth class of plants, Cryptogamia, the fungi whose names and descrip- 

 tions he had found in the works of his predecessors but, since he knew little 

 about fungi himself, the main value of this portion of his book was the application 

 to these fungi of the binomials instead of the polynomial names of Micheli and 

 Dillenius. 



After Linnaeus, the most significant mycological works in the next one hun- 

 dred years, from the taxonornic viewpoint, were those of Persoon, Fries, and 

 Corda. Christiaan Hendrik Persoon was born in South Africa in 1762. At the 

 age of twelve he was sent by his father to Europe for his education. He never 

 returned to Africa, although he kept in touch with his family and never lost 

 his love for his fatherland. He studied in Holland and Germany and later 

 went to France where he remained until his death. A very interesting account 

 of the ancestry and life of Persoon is given by J. L. M. Franken (1937). The 

 classification of fungi that he used in his Synopsis Methodica Fungorum (1801) 

 and his Mycologia Europaea (1822-1828) was the foundation upon which the 

 later mycologists based their work. The number of recognized genera and spe- 

 cies had been greatly increased. The improvements of the microscope, although 

 it was still a rather crude instrument, made it possible to study the manner in 

 which the spores are borne; thus the fungi could be divided into major groups, 

 many of which are still recognized. It must be remembered that by the Inter- 

 national Rules of Botanical Nomenclature the Synopsis 3Iethodica is the authori- 

 tative work for the names up to 1801 of the Uredinales, Ustilaginales, and Gas- 

 teromycetes. Many mycologists believe that it would have been wiser to make 

 that the date of reference for all fungi instead of using Linnaeus (1753), for 

 the Mycetozoa and lichens, and Fries (1821-1832) for the rest of the fungi. 



Probably the work of Elias Magnus Fries (b. 1794, d. 1878), especially his 

 Sy sterna Mycologicum (1821-1832), along with the above-mentioned publica- 

 tions of Persoon, is what gave the great impetus to the taxonomic study of the 

 larger fungi. For the next one hundred years the classification of the Agari- 

 cales and Polyporales especially came to be based upon Fries. One must not for- 

 get, however, that he in turn was dependent upon the clarity of vision of his 

 predecessor, Persoon. Fries did not depend greatly upon the microscope so his 

 knowledge of the smaller Ascomycetes and Fungi Imperfecti was not too good. 



August Carl Joseph Corda, who lived to be only forty (b. 1809, d. 1849), pub- 

 lished a six-volume work, Icones Fungorum (1837-1854), in which he described 

 and illustrated hundreds of microscopic fungi, using for that purpose a micro- 

 scope that we would refuse to consider worth our while but which was good 

 for his time. With the works of Persoon, Fries, and Corda the botanists inter- 

 ested in fungi had at least a fair foundation upon which to build and a begin- 

 ning of an idea of the structural features basic to taxonomy. 



It must be noted that among the foregoing authors there was considerable 

 confusion as to what was meant by the terms "ascus" and "basidium." Appar- 

 ently Fries did not distinguish between the "ascus" of the genus Agaricus 

 and of Peziza. He criticized severely the emphasis of differences which could 



