36 AGRICULTURAL AND INDUSTRIAL BACTERIOLOGY 



tion in milk. Others are capable of producing diseases. 

 Certain species, for example, are commonly associated witli 

 tonsillitis, rheumatism, with the disease strangles in the 

 horse, wound infection, and pus production. 



Diplococcus. — The organisms belonging to this genus are 

 strict parasites. Gram-positive, occurring in pairs, the cells 

 usually somewhat pointed. The most important species is 

 the organism usually associated with pneumonia. 



0O 

 O 



Fig. 16. — Diplococcus. Fig. 17. — Staphylococcus 



Capsulated. 



Staphylococcus. — In this genus the spherical cells are 

 united in more or less irregular masses. They are Gram- 

 positive, and usually parasitic. They are commonly asso- 

 ciated with pus production, wound infection, the develop- 

 ment of boils, abcesses, and similar conditions in the bodies 

 of man and animals. 



Micrococcus. — The organisms of this 



^ " ^ genus are usually not parasitic, but are 



^ ^ • present commonly in water and soil. 



They are frequently Gram-negative, 



occasionally motile, and when grown in 



^ , the laboratory usually develop a yellow 



Flo. 18— MiCEococcus. . „, : „ 



pigment. There are no species of con- 

 siderable economic importance. 



Sarcina. — Organisms belonging to this genus have their 

 spherical cells usually massed in regular packets, consisting 

 of cubes of eight cells each. When grown in the labora- 

 tory pigment is frequently produced, usually yellow in 

 color. 



4 



