

BACTERIA IN THEIR RELATION TO VEGETABLE 



TISSUE. 



BY H. L. RUSSELL. 



The relations of that group of micro-organisms known as bacteria 

 to the animal kingdom have within the past two decades been made 

 the subject of unusual attention. 



No department of the rapidly developing branches of science has 

 been the field of greater activity, yet, strange to say, the relations 

 which these organisms bear to the co-ordinate branch of biology, the 

 vegetable kingdom, have been greatly neglected. 



Botanists have studied bacteria as a class, more or less, in order to 

 determine, if possible, their affinities with other low forms of life, but 

 the greater activity in this field has been largely due to the close 

 relation which they bear to medicine in the etiology of disease. 



In regard to the relations which they bear to and the influence that 

 they exert upon higher plant life, the data we possess are meager. 

 The progress which has already been made in this department of 

 plant pathology comes largely from this side of the Atlantic, and to a 

 prominent American botanist, Prof. T. J. Burrill, belongs the honor 

 of having been the first to work out the causal relation between a 

 specific microbe and, a plant malady (pear-blight, 1878). 



Although Prof. BurrilPs work was done over a decade ago, com- 

 paratively little notice has been taken of it by European writers, 

 with but few exceptions, and the majority of the text-books that refer 

 to it at all regard the case as not thoroughly proven ; but upon what 

 grounds these conclusions are based it is quite impossible for one to 

 understand who has had access to the already widely published data. 



It seems to be a wide-spread belief that plants do not suffer to any 

 great extent from the attacks of these micro-organisms. The reasons 

 usually assigned for this so-called immunity are various. Chief 

 among them, however, is that which bases the freedom of plants from 

 bacterial attack upon the acidity of the plant-tissue. Other subsidi- 

 ary reasons are also advanced by various authors. 



