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EXPERIMENT STATION BULLETINS 213 



Streptococcus. — A epeciee of micrococci arranged in chaiLB. 



Tetrad. — A grouping of four micrococci. 



Threads.— The joining of bacilli end to end in rows. 



Toxicogenic. — Applied to bacteria producing poisons. 



Translucent. — Semi-transparent. 



Vegetative cell. — Cell capable of multiplying, v 



Vibrio.-^A comma shaped micro organism. 



Veasts. — Unicellular plants which multiply by budding. 



Zooglea. — A massing of bacteria by means of an adhesive cell wall. 



Zymogenic. — Applied to bacteria producing fermentation. 



INTRODUCTION. 



The science of bacteriology has entered into such an intimate relation 

 with the farmer, because of its connection with the dairy, the soil, the 

 silo, the diseases of animals and plants, and his surroundings, that some 

 knowledge of it becomes indispensable to him. Thus far he has been met 

 with reports and treatises of a technical or semi-technical character, 

 simply because reports and treatises assume that an elementary knowledge 

 of this subject exists, and because a report or treatise cannot be written 

 absolutely free from terms of a technical nature. Explanations are not 

 satisfactory where ihey are short and unsystematic. 



The Michigan experiment station shall strive to make the work in 

 bacteriology useful to every man who can read the English language and 

 is interested in the matters of which this science treats. To accomplish 

 this object, short and simply written bulletins will be issued from time to 

 time, paving the way for the reports of experiments which must be of a 

 semi- scientific character from their very nature. It is desired that 

 these bulletins be near at hand for immediate reference and that they be 

 wide enough in scope to answer and explain the various questions which 

 naturally arise from a perusal of bulletins and in practical life. 



In a few words, a general survey of bacteriology, covering those phases 

 of the science especially applicable to agricultural interests, will be 

 undertaken. 



TEEMS. 



Some confusion prevails in regard to the terms applied to the organ- 

 isms constituting the class of life included in bacteriology. Perhaps the 



most specific general term in use and most representative is 



Bacteria. bacteria, that which enters into the formation of the term 



Micro- organ- bacteriology; yet a term so significant as micro-organisms — 



isms. small organisms — must not be disregarded. Again we find in 



Microbes, the word, microbes, about the same fullness of meaning as in 



micro-organisms. Sometimes the most non-specific term. 

 Germs. germs, is employed, evidently because it is short and euphon- 



ious, rather than from any value it possesses in this connection. 



