INFECTION WITH SARCINA TETRAGENA 421 



blood very promptly after the injection of the serum. A 

 part of the action of the immune serum seems to be anti- 

 toxic. 1 



INFECTION WITH SARCINA TETRAGENA (GAFFKY), 

 MIGULA, 1900. 



SYNONYM: Micrococcus tetragenus, Gaffky, 1883. 



Should the death of the animal not occur within the first 

 twenty-eight to. thirty hours after inoculation, but be post- 

 poned until between the fourth and eighth day, it may 

 result from the invasion of the tissues by the organism now 

 to be described, viz., sarcina tetragena. 



This organism was discovered by Gaffky, and was subse- 

 quently described by Koch in the account of his experiments 

 upon tuberculosis. It is often present in the saliva of 

 healthy individuals and is commonly present in the sputum 

 of tuberculous patients. Koch found it very frequently in 

 the pulmonary cavities of phthisical patients. It, however, 

 plays no part in the etiology of tuberculosis. It is principally 

 of historic interest, being of little pathogenic significance. 



It is a small round coccus of about IM transverse diam- 

 eer. It is seen as single cells, joined in pairs, and in 

 threes; but its most conspicuous grouping is in fours, from 

 which arrangement it takes its name. In preparations made 

 from cultures of this organism it is not rare to find single 

 bodies which are much larger than the other individuals in 

 the field. Close inspection reveals them to be cells in the 

 initial stage of division into twos and fours. A peculiarity 

 of this organism is that the cells are bound together by a 

 transparent gelatinous mass. 



1 Cole, Jour. Am. Med. Assoc., 1912, lix, 693 and 1913, xli, 663. 



