ATTITUDE; OF PATHOLOGISTS AND BACTERIOLOGISTS. 13 



of vegetables, Carman's cabbage-rot, Sereh disease of sugar-cane, Comes's gum diseases, 

 Halsted's celery-blight, I/udwig's white slime-flow, Ludwig's brown slime-flow. 



Bacteria are not recognized as the cause of any grape diseases by Viala in the second 

 edition of his Diseases of the Vine, published in 1887. In the third edition of this book, 

 published in 1893, two French diseases of the grape are said to be due to bacteria: Pour- 

 riture des grappes and maladie du coup de pouce. 



In 1894, in the English translation of Hartig's Diseases of Trees, edited by H. Marshall 

 Ward, it is stated that "Only in extremely isolated cases has it been placed beyond doubt 

 that these low organisms are the primary cause of disease in plants." Wakker's disease 

 of hyacinth, the wet-rot of potatoes, the tubercle of Aleppo pine and of the olive tree, and 

 the blight of the pear are more or less grudgingly admitted to be diseases of this class. 



Concerning the first, it is said that "under normal conditions the bacteria do not 

 attack perfectly healthy bulbs" and that "a species of Hyphomyces almost always accom- 

 panies the disease. ' ' Under wet-rot of the potato the editor hazards the following statement : 



It is extremely probable that in this and other similar cases the minute bacteria travel in the 

 tissues down the tubes of the filaments (hyphae) of the fungus, feeding on the decomposing pro- 

 toplasmic contents of the latter. 



Concerning pear-blight we have the following : 



Lately a disease of apple and pear trees has been described by J. Burrill, of Urbana, 111., under 

 the name of "blight," the cause of which, according to this investigator, is to be ascribed to the 

 invasion of a bacterium. The disease appears to bear resemblance to the tree-canker produced by 

 Nectria ditissima; and as, in the case of this fungus, large numbers of small gonidia resembling 

 bacteria are produced in the cortex, it remains to be seen whether this disease has not been errone- 

 ously ascribed to a bacterium. 



Prillieux in his text-book on Diseases of Plants, published in 1895, devotes 3 7 pages 

 to bacteria. He admits the following as diseases of bacterial origin: Rose-red disease of 

 wheat grains; wet-rot of potatoes; white-rot of hyacinths; potato scab; gangrene of potato 

 stems ; disease of grape bunches in France ; Mosaic disease of tobacco ; blight of mulber- 

 ries; point-rot of tomato fruits; black spots in potato tubers; spot disease of sorghum; 

 yellow disease of hyacinths; gummosis of the vine; pear-blight; olive tubercle; pine 

 tumors; white slime-flow of trees; brown slime-flow of trees; black slime-flow of trees. 

 In general, Prillieux's book gives the impression of one who works rapidly and only with 

 the microscope. 



Von Tubeuf in his book on Plant Diseases, published in 1895, devotes 10 pages out 

 of 611 to this class of diseases. In the introduction he says: 



While only a few diseases of men and warm-blooded animals are due to the true fungi, etc. 

 * * * the infectious diseases of plants are caused almost exclusively by fungi. Even 



the few bacterial diseases thus far described are almost all still incompletely investigated and abun- 

 dantly doubtful in two directions. In case of some we have unquestionably to do with a plant 

 disease, more or less exactly known; and it is only the cause of the same which is not yet fully 

 investigated. In these cases, the question then arises whether the disease is due to a microorganism 

 at all and whether this is or is not really a bacterium. But in other cases it is doubtful whether 

 the phenomena, in connection with which the appearance of the bacteria has been observed, are 

 truly to be considered as diseases. On this account we will speak with reserve and briefly upon the 

 bacterial diseases, a labor essentially lightened by the bringing together of the bacterial diseases in 

 the Lehrbuch der niederen Kryptogamen of Professor Ludwig, 1892, and the critical examination of 

 the same from the bacteriological standpoint, by Dr. W. Migula. 



Then follows a brief account of the 5 diseases reckoned by Migula as of bacterial 

 origin, and also the mention of 17 others ascribed to bacteria by various persons, and 

 concerning which Dr. von Tubeuf says in the introduction, speaking very cautiously, as 

 one unfamiliar with the subject : 



But we will also here refer briefly to those diseases in which bacteria are suspected of being 

 the cause. 



