BESSEY: MYCOLOGY Til 



interesting book Advance of the Fungi (1940), especially with reference to the 

 great epiphytotic of late blight of the potato. In 1845 when this attacked the 

 crops of Great Britain and Ireland and other parts of Europe there were two 

 opposed groups of scientists. One, headed by Berkeley, insisted that the fungus 

 associated with the disease (later named PJiytopMhora infestans [Mont.] De 

 Bary) was the real cause of the trouble, whereas the other group, led by Lindley, 

 maintained that the disease came first and was due to soil or weather conditions 

 or to the "running out" of the varieties. As for the ever-present fungus, some 

 held with Lindley that it was simply growing upon the already diseased tissue, 

 but was not the cause of the disease. Others agreed with Unger and Fries in 

 considering the fungus the product of the diseased tissue. 



The Structure and Life History of Fungi 



In Great Britain Berkeley was for many years the leading student of fungi, 

 including those whose study required the use of the compound microscope. He 

 described many hundreds of species of hitherto unrecognized fungi and was 

 the backbone of the group which maintained that many of the smaller fungi 

 were actual parasites (in the present sense of the word) upon the hosts. On 

 the Continent, after Corda's death in 1849, the study of the smaller fungi as 

 well as of the structure of the larger fungi was carried on by Joseph Henri Le- 

 veille (who lived from 1796 to 1870), and very many were carefully described and 

 illustrated by him, even though he still maintained that they originated as exan- 

 themata upon the host plants and were not really parasites. But the researches 

 of Berkeley, Fresenius, and especially Montague (b. 1784, d. 1866) and Tulasne, 

 rapidly brought the scientific world to abandon this idea. Persoon (1801) said, 

 it is true, of some fungi, "Locus natalis . . . in plerisque parasiticus est ut 

 pleraeque plantae aphyllae parasiticae sunt," but it is not certain whether he re- 

 garded a parasite as we do as obtaining its nourishment at the expense of, and 

 causing injury to, its host, or whether he used the term in the old classical sense 

 of a person obtaining his meals at the table of another. Schleiden in the third 

 edition of his Grundziige der Wissenschaftlichen Botanik (1850) took a midway 

 position on the question. He did not regard the rusts and smuts as independent 

 organisms but only as diseases of plants. On the contrary, the fungi which grew 

 in the intercellular passages of their hosts and emerged through the stomata he 

 considered true parasitic plants. His work was the leading botanical textbook 

 in Germany and had great influence upon the ideas of students of mycology. 

 However, since he did not publish descriptions of new species of fungi, it re- 

 mained, apparently, without much influence upon mycological systematists, who 

 did little in the way of careful intensive study of the structure and life histories 

 of the individual fungi. 



This newer method of the study of fungi was undertaken in France by Louis 

 Rene Tulasne (b. 1815, d. 1885) and his brother Charles (b. 1816, d. 1884). The 

 former did the more intensive mycological study, the latter made the marvelously 

 beautiful illustrations for their publications. It soon became apparent to them 

 that some fungi had more than one type of spores and that these did not always 

 germinate in a similar manner. In 1853 they demonstrated that spores of some 

 rusts germinated by the formation of long hyphae or germ tubes and that others 



