38 



CELL FORMS 



tion between the two can be made only by examining the 

 organism ahve and moving in a Hquid. The vibrio shows a 

 characteristic spiral twisting motion. Very long, flexible 



Fig. 35.— Cocci. 



Fig. 36.— Bacilli. 



spirals are usually named spirochetes (Fig. 41). The spir- 

 ochetes are motile but flagella have not been shown to be 

 present. 



Fig. 37.— Short bacilli 



Fig. 38.— Curved bacilli. Only 

 the one in the center of the field is 

 in focus. The others curve out of 

 focus. 



Besides the three typical cell forms^ bacteria frequently 

 show very great irregularities in shape. They may be 



1 The three typical cell forms might be reduced to two the sphere and 

 the cylinder, if one chose to consider the bacilli as straight or curved cylinders 

 and the spirilla as twisted cylinders. The above division into three typical 

 cell forms is practically universal. 



