Apeil 18, 1902.] 



SCIENCE. 



605 



genus Alternaria and of the forin-gentis 

 Fnsarnim. 



Very little was known relative to the 

 treatment of plant diseases beyond the fact 

 that mildews in hothouses were supposed 

 to be induced by draughts of cold air and 

 to be partially preventable by the use of 

 sulphur dust; that wheat smut appeared 

 to be partially controllable by soaking the 

 seed-wheat in a solution of copper sulphate, 

 and that sulphur dust was a remedy for 

 Oidium of the vine. 



Little or nothing was known with regard 

 to varietal or individual resistance of 

 plants. In a general way, it had been 

 observed by many that, under what seemed 

 identical conditions, some plants sickened 

 while others remained healthy, but it was 

 quite generally believed that this was due 

 to the fact that there had been no good 

 opportunity for the fungus to infect the 

 plant, rather than that the plant itself had 

 any special power of resistance. This idea 

 was yet unborn, or, at least, had not come 

 to any prominence among pathologists. 



Among the great mass of farmers and 

 other growers of plants, the rusts, smuts, 

 mildews, etc., were accepted as the will of 

 God, or as a matter of course, and it never 

 entered their heads that anything coald be 

 done to lessen the ravages of these 

 troubles. 



Nothing whatever was known about bac- 

 teria as the cause of plant diseases except 

 to two or three workers who were just 

 beginning their studies in this field. I 

 refer especially to Burrill in America and 

 Prillieux in France. It was also not gen- 

 erally recognized that algas could cause dis- 

 ease in plants. Little or nothing was 

 know about enzymes, ions, cell nuclei or 

 symbiosis as important factors in plant life. 



Let us now for a few minutes glance at 

 what has been accomplished in the last 

 twenty years. From being a mere rule of 

 thumb, plant pathology has become a well- 



established branch of botanical science, the 

 study of which has been pursued in many 

 places with astonishing ardor and excellent 

 results. Among others, the following 

 authors have published general works on 

 plant diseases within the period named: 

 Sorauer, Frank, Hartig, W. G. Smith, 

 Kirchner, Scribner, Ward, Comes, Prilli- 

 eux, von Tubeuf, Massee. Sorauer, Frank, 

 Hartig and Ward have published several 

 different books on plant diseases. Books 

 by Hartig and von Tubeuf have been trans- 

 lated into English, and Kirchner 's book has 

 recently been done into Italian. In some 

 cases elaborate treatises have been written 

 on the diseases of small groups of plants, 

 e. g., Viala's ' Diseases of the Vine ' (three 

 editions), and Erickson's 'Grain Eusts.' 

 Sorauer and Kirchner have also both pub- 

 lished atlases of plant diseases, illustrating 

 the more common diseases with colored fig- 

 ures, which, however, in many cases, it 

 must be confessed, could be improved upon. 

 In this enumeration the extremely useful 

 ' Host Index ' by Farlow and Seymour 

 should not be forgotten, nor Sturgis' com- 

 pact ' Bibliography. ' 



In the publication of authoritative gen- 

 eral treatises on plant diseases, the United 

 States has not kept pace with Germany. 

 Scribner 's little book on ' Fungous Diseases 

 of the Grape, etc' (1890), is all that I can 

 recall. That no book at all comparable 

 with the handbooks of Sorauer, Frank, 

 Kirchner or von Tubeuf has yet appeared 

 in the United States is a matter for some 

 wonder, considering the member of us who 

 are affected with an itch for writing. It is 

 also a matter for regret, considering the 

 extent of our territory, the number of our 

 plant diseases, and the character of our 

 population. There is now a demand in this 

 country for several good manuals of phy- 

 topathology, and these books are the more 

 to be desired because European manuals 

 only very imperfectly outline American 



