CHAPTER III. 



Morphology 

 Defined. 



Micro-cocci. 



Bacilli. 



DESCRIPTION OF THE MOST IMPORTANT BAC- 

 TERIA, METHODS OF MULTIPLICATION, ETC. 



Morphology is that branch of science which 

 treats of the classification of bacteria with re- 

 gard to their shape, outHne, structure and their 

 methods of grouping. Placed in broth, 

 bouillon or other substance they are cultivated, 

 and much useful information has been gained 

 with regard to the habits, etc., of these tiny 

 specimens of vegetable life. 



It has been found by studying them under 

 the microscope, that all bacteria of any import- 

 ance are either "sphere," "rod," or "spiral" 

 shaped, and so they are divided into these three 

 classes. ,^ 



The spherical may be perfectly 

 ^ round like a ball or marble, or they 

 may be oval or egg-like; they vary 

 in size and many are imperfect in 

 shape. The name given to all bac- 

 teria of this formation is "cocci" or "mi- 

 crococci." 



The rod-shaped may be long or 

 ^^- short, square or round at the ends, 



thick or thin, but all bear the com- 

 mon name of "bacilli." The 

 largest number of disease germs 

 are of this clasg, 



38 



Spheres. 



Rods. 



