480 



SCIENCE 



[N. S. Vol. XLI. No. 1057 



parasitology is of course only a branch of 

 mycology. 



Plant pathology is a subject of very 

 recent development and can scarcely be 

 said to have existed before the middle of 

 the last century. During the period from 

 1830 to 1850 attention began to be given 

 to this subject. Unger, Wiegmann, Meyen, 

 Raspail and Regel wrote on the diseases of 

 plants. These authors took up the subject 

 from the standpoint of general botany and 

 human pathology rather than mycology. 

 Some very curious ideas prevailed ; e. g., it 

 was believed that fungi such as rusts were 

 produced by the puncture of insects (Ras- 

 pail, 1846). Unger 's idea was that certain 

 fungi were outgrowths or modifications of 

 the tissues of the diseased plant. These 

 and earlier works contained various more 

 or less academic discussions of various dis- 

 eases, based largely upon erroneous ideas 

 of the structure and nature of the parasite 

 as well as the host. As an illustration of 

 how persistent medieval ideas and concep- 

 tions are I may cite a recent instance. A 

 correspondent, in explaining the cause of a 

 strawberry disease, states that it is due to 

 "elemental debasement." This reminds 

 one of the "original sin" of the old the- 

 ology, to which it may perhaps be closely 

 akin. 



Under the influence of the important 

 contributions to the knowledge of the cellu- 

 lar structure and tissues of plants, which 

 were made during this period, together 

 with the work of contemporary mycolo- 

 gists, the foundation was laid for a more 

 rational and correct interpretation of plant 

 diseases and parasites. 



Since the great majority of plant diseases 

 are caused by fungi, it is quite proper that 

 mycology should be considered the chief 

 cornerstone of this branch of science and 

 should be thoroughly understood by the 

 plant pathologist. 



In order to get a proper conception of 

 any subject and to understand and appre- 

 ciate its present condition and needs, a 

 knowledge of its past history and develop- 

 ment is necessary. It is quite appropriate 

 that Florence, the chief seat of learning 

 and the leader in literature, religion, art 

 and science during the Renaissance and be- 

 ginning of the modern era, with the illus- 

 trious names of Dante, Savonarola, Raphael 

 and Michael Angelo should have pro- 

 duced the great botanist, Micheli, who may 

 be justly considered the father of mycology. 

 His great work, "Nova Plantarum Gen- 

 era," published in 1729, was devoted 

 largely to the description and illustration 

 of fungi. This work remained unsurpassed 

 for fifty years and is still recognized as a 

 classic on this subject. Micheli 's collec- 

 tions of fungi are still preserved in Flor- 

 ence beside those of Cesalpini. Some of his 

 specimens compare favorably with those of 

 much more recent mycologists. 



Following Micheli some twenty-five years 

 later came Battara, also an Italian. Dur- 

 ing the latter half of the eighteenth cen- 

 tury Tode, Hoffman, Batsch, Bulliard and 

 Persoon made important contributions to 

 descriptive mycology. In the early part of 

 the nineteenth century the most distin- 

 guished students of the subject were Per- 

 soon, Greville, Wallroth, Link, Sowerby, 

 Fries and Corda in Europe, while in 

 America the illustrious Schweinitz laid the 

 foundations of American mycology and 

 took rank among the first mycologists of 

 the world. Following him in this country 

 came Curtis, Ravenel, Peek, Ellis, Farlow 

 and Burrill. Most of the work of the early 

 writers was systematic, and may appear to 

 some of us to be very crude and unsatis- 

 factory, but when we consider the condi- 

 tions under which they labored and the 

 tools and technique available, it will be 

 found that their work is of as high quality 



