SARCINA FORMS 53 



When freshly isolated from human lesions streptococci often show only a slight 

 virulence for animals. Hence massive doses are indicated and intravenous or 

 intraperitoneal injections. The guinea-pig is not very susceptible to streptococci; 

 the rabbit and white mouse being the animals of choice. 



In nondiphtheritic anginas, puerperal fever, ulcerative endocarditis 

 and coccal enteritis it is the streptococcus which is usually the cause. 

 It has been claimed that acute articular rheumatism is due to a short- 

 chain streptococcus (M. rheumaticus), which is best isolated from 

 material from an acute joint infection, but may also be isolated 

 occasionally from the blood. It produces much acid and clots milk in 

 two days. The growth is described as being more luxuriant than that 

 of S. pyogenes. It is about 0.5/4 in diameter. 



The majority of investigators have reported streptococci from acute joint inflam- 

 mations and bacilli from chronic infectious joint affections. Goadby has considered 

 a streptobacillus, somewhat resembling Ducrey's bacillus of chancroid, which 

 exhibits marked pleomorphism and Gram variations, and grows best on egg albumin 

 agar of plus 3 reaction as the cause of arthritis deformans and alveolar osteitis. 

 Inoculation of cultures of this organism into or around the knee-joints of rabbits 

 has produced lesions similar to those of rheumatoid arthritis. 



SARCINA FORMS. 



These are best observed in hanging-drop preparations, when they 

 can be seen as little cubes, like a parcel tied with a string, and by noting 

 them when turning over, it will be seen that they are different from the 

 tetrads which only divide in two directions of space. At times the 

 packet formation is not perfect and it will be difficult to distinguish 

 such as sarcinae. All sarcinae stain by Gram. If the staining of 

 sarcinae be too deep it may obscure the lines of cleavage. Sarcinae are 

 nonmotile. 



Various sarcinae have been isolated from the stomach, especially 

 when there is stagnation of stomach contents. Sarcinae have also been 

 found in the intestines. In plates the S. lutea is frequently a contami- 

 nating organism, being rather constantly present in the air. The 

 demonstration of sarcina morphology should always be made from 

 liquid media, as bouillon. Urine makes an excellent medium. 



MICROCOCCUS FORMS. 



This grouping includes all cocci which do not show chain or packet 

 formation. It will be found convenient to divide them into two classes 



