PART VIII. 



BACTERIA. 



CHAPTER LII. 



BACTERIA: THEIR MORPHOLOGY AND 

 REPRODUCTION. 



I. The Bacteria are a group or class of organisms included in 

 the Thallophytes, and sometimes designated Schizomycetes or 

 splitting-fungi. They appear, however, to exhibit little or no 

 relationship to the true fungi, except that, like the latter, they are 

 devoid of chlorophyll. 



The body of each individual bacterium is of the simplest 

 character, consisting of 



a single cell, which is oo (f^C:>^f "^ c^ 



most frequently either o°% °'^'^^*^ ^S^D ^^^ 



spherical, rod - shaped, 

 or bent in the shape of 

 a spiral or bow (Fig.. 



260). When spherical, Fig. 260. -Forms of bacterial cells: i. Coccus; 2. 



the bacterium is termed ''""""= ' '• """" ' *' ='■'""'■'"• 

 a coccus (i), if rod-shaped or cylindrical and more than twice as 

 long as broad it is known as a bacillus (2), while the term 

 bacterium is not only employed in a general sense to denote any 

 organism belonging to the Schizomycetes, but is also used in a 

 restricted sense for a rod-shaped organism, which is shorter than 

 a bacillus. 



The form of bacterium known as a vibrio (3) is bent like a bow, 

 that shaped like a cork-screw being spoken of as a spirillum (4). 



3 c 769 



