VIL] MICROCOCCUS. 61 



and physiological function, into : (a) septic, (b} zymogenic, 1 

 (c) chromogenic, and (d) pathogenic micrococci. 



(a) The septic micrococci are micrococci that occur with 

 other septic bacteria, wherever there is decomposition of 

 organic matter in solids or in fluids. There exists a large 

 number of species of such micrococci, differing from one 

 another in size and mode of growth. They are widely 

 distributed in the air, and contamination by air is often 

 followed by the appearance of micrococci. They also occur 

 in the body of man and animals wherever there is dead 

 tissue, in which they grow well and copiously. Of this kind are 

 the micrococci found in ordinary pus (Ogston), in the normal 

 oral cavity (on the filiform papillae of the tongue and on the 

 mucous membrane), in the bronchial secretion in ordinary 

 catarrhal exudations (nasal cavity, bronchi, &c.), on the free 

 surface of intestinal and other ulcerations, in the cavity of the 

 small and large intestine, and in the epidermis of the normal 

 skin (Bizzozero). 



(b} Zymogenic micrococci are micrococci associated with 

 definite chemical processes, (a) Micrococcus ureae, causing 

 the ammoniacal fermentation of urine (aerobic, Pasteur), 

 occurs singly, as dumb-bells or chains, and as zoogloea. (/?) 

 The micrococcus of the mucoid wine fermentation produces 

 (Pasteur) a peculiar mucoid change in wine and beer, and 

 occurs chiefly in chains, (y) The micrococcus causing phos- 

 phorescence in putrid meat and fish (Pfliiger) forms chiefly 

 zoogloea (aerobic). 



(c) Chromogenic micrococci (Schroter, Cohn). These 

 micrococci are characterised by their power of forming 



1 I adopt this term from Fliigge : Fermente und Mikroparasiten, 

 Leipzig, 1883. 



