222 PHARMACEUTICAL BOTANY 



**Fresh-watej; forms with easily discernible sheath 

 Crenothrix. 

 2. Filaments branched. 



B. Cell contents with sulphur granules Thiothrix. 



Family VI. Beggiatoaceae. Thread-like, without a capsule, but 

 with an undulating membrane. Cell contents show sulphur granules. 



A. Threads apparently not septated, septa only faintly visible 

 with iodine staining. Colorless or faintly rose-colored Beggiatoa. 



Sporulation. A large number of bacteria possess the power of 

 developing into a resting stage by a process known as sporulation 

 or spore formation. Sporulation is regarded as a method of resisting 

 unfavorable environment. This is illustrated by the anthrax 

 bacilli which are readily killed in twenty minutes by a 10 per cent, 

 solution of carbolic acid, and able, when in the spore condition, to 

 resist the same disinfectant for a long period in a concentration of 

 50 per cent. And, while the vegetative forms show little more 

 resistance against moist heat than the vegetative form of other 

 bacteria, the spores will withstand the action of live steam for as long 

 as ten to twelve minutes or more. 



Whenever the .spores are brought into favorable condition for 

 bacterial growth, as to temperature, moisture and nutrition, they 

 return to the vegetative form and then are capable of multiplication 

 by fission in the ordinary way. 



Reproduction. Bacteria multiply and reproduce themselves by 

 cleavage or fission. A young individual increases in size up to the 

 limits of the adult form, when by simple cleavage at right angles to 

 the long axis, the cell divides into two individuals. 



Morphology Due to Cleavage. According to limitations imposed 

 by cleavate directors, the cocci assume a chain appearance, or a 

 grape-like appearance, or an arrangement in packets or cubes having 

 three diameters. This gives rise to the 



Staphylococcus (plural, staphylococci), from a Greek word referring 

 to the shape of a bunch of grapes. 



Streptococcus (plural, streptococci), from a Greek word meaning 

 chain-shaped. 



Sarcina, package-shaped or cubical. 



