CHAPTER II 



GENERAL MORPHOLOGY REPRODUCTION- 

 CHEMICAL AND PHYSICAL PROPERTIES 



GENERAL MORPHOLOGY 



Bacteria (sing., Bacterium). In introducing the sub- 

 ject of morphology a few words as to the technique of 

 observing bacteria will not be amiss. The compound 

 microscope is necessary to all microbiological work. 

 Since this book is devoted to principles, a detailed 

 description of the instrument and its operations would 

 be foreign. Let it suffice to say that the compound 

 microscope is a series of finely ground lenses by which 

 exact pictures in definite magnification can be obtained. 

 An object to be examined is placed upon a glass slide 

 and covered with another but much thinner glass cover. 

 This is laid upon the table of the instrument and the 

 tube holding the lens placed at a proper distance to 

 obtain the best light and clearest picture when viewed 

 through the eye-piece end. For nearly all microbiologi- 

 cal observations it is advisable to introduce between the 

 object glass and the lens a drop of pure cedar oil in 

 order that light can be made pure and concentrated. 

 The microscope is also used to examine the colonies 

 of bacteria. Bacteria are studied either in the fresh 

 living condition or when stained by appropriate dyes. 



Bacteria are exceedingly small single cells, in their 



