SHAPE OF MICROORGANISMS 



25 



are just as likely to produce their peculiar effect as are the normal 

 organisms. Hence, we consider their changed shape as being due 

 to environmental conditions which have caused a change only m 



shape. 



Reproduction. — Bacteria quickly decompose the body of an 

 ox. Plants and fruits quickly decay. Millions of tons of organic 

 matter are carried to rivers, lakes, and oceans each year. Bacteria 



^^ ••,»,**' 



Fig. 6 — DIplococci (after Heine- 

 mann). 



Fig. 7. — Streptococci (after Heine- 

 mann). 



change all of this into a residual ash and gaseous products. They 

 modify the whole surface of the earth. One may wonder how 

 it is possible for such small plants to accomplish such gigantic 

 tasks. This is due to the rapidity of multiplication. The bacilli 

 grow until they have reached a certain size, then they divide into 

 two daughter cells. These in turn grow to maturity and like- 

 wise divide. At times on division the various cells may remain 

 connected together having the appearance of a chain. Such a 

 chain of organisms is called streptobaccilli. 



The cocci may divide in one, two, or three planes. When they 

 divide in the same plane and the daughter cells touch at one side 

 only and have the appearance of closely strung beads, they are 

 known as streptococci. They may divide in one plane followed 

 by division in another at right angles to the first, thus forming a 



