158 ELEVENTH ANNUAL REPORT 



DEPARTMENT OF BACTERIOLOGY 



Since the last report this department has been working along 

 the following lines: 



Study of the bacteriology of ensilage. In this connection a 

 series of experiments in taking temperatures in the silo by 

 electrical means has been completed and another begun. 



Study of the root tubercles of the leguminous plants. 



Study and treatment of leaf and fruit spot of apple. 



Study of life-history and treatment of black knot. 



Study of the fungi and bacteria concerned in the decay of 

 fruit with especial reference to the apple. 



As ah introduction to future bulletins the following sum- 

 mary of the principal general facts in regard to bacteria is 

 here given: 



Any one who gives the subject a moment's consideration can- 

 not help being impressed by the wonderful variety of the 

 plants which make up the grand division of living things 

 known as the vegetable kingdom, but no one, who has not given 

 special study to the subject, can have any adequate idea how 

 great and how wonderful this variety is. Besides the plants 

 which make up the greater part of the vegetation that clothes 

 the earth's surface, and at the same time offer to man materials 

 for food, clothing, houses, and innumerable' luxuries, there are 

 others which, while of the highest interest to the botanist or 

 biologist, receive from the majority of people very little con- 

 sideration, either because of their lack of economic impor- 

 tance or because of their small size, which renders them diffi- 

 cult of observation. Such plants are the mosses, the lichens, 

 the alg^, and the fungi, which are considered to occupy a 

 lower position in the scale of vegetable life than those with 

 which we are most familiar. Lower still than these is a group 

 of plants which, although the smallest members of the vege- 

 table kingdom, are far from being the least important. Not 

 only are they of interest to the botanist, but more and more 

 it is coming to be recognized that they are of great economical 

 and therefore of great practical importance. These plants are 



