136 GENERAL BIOLOGY 



transverse, producing strings or chains of cells 

 (Streptococci), or they may be alternatingly in two 

 vertical planes, producing groups of four, or, finally, 

 the planes of division may occur in the three dimen- 

 sions of space, producing groups of eight (Sarcina) 

 in a cubical aggregate. 



FIG. 50. Types of Bacteria, illustrating various modes of fission : 

 A, simple coccus form; B, diplococcus (fission in one plane only, the pair 

 separating as formed; E, chain form (streptococcus), the fission all in one 

 plane, but the cells remaining together; C, division in fours (tetrads) in 

 one plane ; D, division in three planes to produce cubes or bale-like 

 masses (sarcina) ; G, division planes at random, to produce masses 

 (staphylococcus) ; F, flagellated cocci (nitrogen-fixing bacteria of the soil); 

 H, rod-form (bacillus) ; I, bacillus with flagella at one end (putrefactive 

 bacteria); J, with flagella all over the cell body (typhoid bacillus). 



Budding. -- From reproduction by fission of the 

 parent body, to reproduction by cutting off of a 

 small portion of the body, is a short step. In the 

 latter case the individual identity of the parent 

 organism is unaffected, and the part budded off 

 develops into the specific type by individual growth 

 and differentiation. Such a process of reproduction 

 is known as gemmation or budding and is well-nigh 

 universal in the plant kingdom as well as in those 



