Bacteria in Relation to Plant Diseases. 



By hRvviN F Smith. 



Part I. — An Outline of iVIethous of Work. 



GENERAL REMARKS. 



The following outline of methods for the stncly of bacterial diseases of ]ilants, 

 which are now in use in the Laborator)- of Plant Patholog)-, ITnited vStales ] )eparl- 

 nient of Agriculture, has gradually assumed its present shape as a result of the 

 writer's field, hot-house, and laborator)- experiments during the past thirteen )ears. 

 In nearh' the same shape, so far as arrangement is concerned, but in a less complete 

 form, it was published in the American Naturalist in iRgfi.* 



The scheme here presented is entireh' practicable and is belie\'ed to be not nu)re 

 extended than the exigencies of the case require; in the interest of better methods 

 of work in plant patholog)' it is recommended to all who contemjilate a special 

 stud^• of bacterial diseases of j^lants, and also particnlarh- to those who intend to 

 describe and name species of bacteria, whether jiathogenic or nonjjathogenic. Those 

 who doubt the necessity for so nnicli work are advised to read procedures recom- 

 mended for the study of bacteria by a committee of the American Public Health 

 Association, and the earlier paper by H. Marshall Ward (Pibliog., III).t It would 

 be still more to the point if they would isolate a dozen bacterial organisms from the 

 soil, air, or water, and undertake faithfull}- to identif}- them b)- means of any of the 

 older descripti\'e works, r. ^., Eisenberg's Diagnostik or vSaccardo's S}lloge Fun- 

 gorum, or e\-en b}- such recent manuals as those of Sternberg, Lehmann & Neumann, 

 Fliigge, Migula, or Chester (Bibliog., Ill), p;^•eryone who has carefull)- incjuired 

 into the matter knows that the brief statement of the behavior of an organism on 

 nutrient agar, on gelatin, and on two or three other media, with jierhaps a loose 

 statement of its color and size, no longer constitutes a description which describes. 

 Such accounts, of which there are a great many, usually fail to mention just those 

 things which might serve to distinguish the organism from its fellows. If a new 

 species is not to be described so that it can be identified b}- others, what then is the 

 use of any name or an}- description ? The name will only serve to encumber future 

 synon}'my and to recall the incapacity of its author. 



*The bacterial diseases of plants: A critical review of tihe present state of our knowledge, 

 parts i-vi. Am. Xat., Angust and September, 1896. 

 tFor Bibliograpby see end of volume. 



