608 NON-PATHOGENIC MICROCOCCI. 



surface is covered by a white layer of micrococci ; development usually 

 ceases before complete liquefaction has occurred. Upon agar and upon 

 blood serum a white layer is developed, which presents nothing characteris- 

 tic ; blood serum is not liquefied. Upon potato a very scanty, thin, color- 

 less layer, which later appears as a collection of white, button-like masses. 



208. MICROCOCCUS OVALIS (Escherich). 



Found frequently in meconium and faeces of milk-fed infants. 



Morphology. Micrococci of from 0.2 to 0.3 n in diameter, frequently 

 seen as oval cells 0.6 to 0.7 n long and 0.3 /* broad, in the middle of which 

 a commencing line of division may sometimes be seen ; sometimes in short 

 chains. 



Biological Characters. An aerobic and facultative anaerobic, non- 

 liquefying micrococcus. Grows in the usual culture media at the room 

 temperature. Upon gelatin plates forms very small colonies which are in 

 no way characteristic. In gelatin stick cultures small, white colonies are 

 developed along the line of puncture, and no development occurs upon the 

 surface, or a scanty, colorless ring of growth surrounds the point of punc- 

 ture. Upon potato a tolerably abundant growth occurs, consisting of a 

 small, white layer. In milk it causes an acid reaction, and coagulation after 

 several days. 



209. DIPLOCOCCUS CORYZ^E (Hajek). 



Found in nasal mucus in acute nasal catarrh. 



Morphology. Large diplococci, flattened along the line of contact; re- 

 semble short bacilli with round ends. 



Biological Characters. Anaerobic, non-liquefying micrococcus. Grows 

 in the usual culture media at the room temperature. Upon gelatin plates 

 forms white, glass-like, slightly elevated colonies. In gelatin stick cultures 

 the growth resembles that of Friedliinder's bacillus at first, but the super- 

 ficial growth is flatter after some days. Upon the surface of agar forms a 

 diffuse layer. 



210. MICROCOCCUS FINLAYENSIS (Sternberg). 



Obtained by Finlay in cultures from the liver and spleen of a yellow- 

 fever cadaver. 



Morphology. Micrococci, from 0.5 to 0.7/* in diameter, solitary, in 

 paii*s, or occasionally in groups of four; also in irregular masses. Like 

 other staphylococci, the cocci are seen, in properly stained preparations, to 

 be made up of two hemispherical portions. 



Biological Characters. An aerobic, liquefying, chromogenic micro- 

 coccus. Grows slowly at the room temperature in the usual culture media. 

 In gelatin stick cultures growth occurs along the line of puncture and lique- 

 faction near the surface; the cup shaped cavity which is slowly formed is 

 lined with a very viscid, opaque, pale- yellow layer of cocci. Upon the sur- 

 face of agar a viscid layer having a pale-yellow color is formed. Not path- 

 ogenic for rabbits or guinea-pigs. 



211. MICROCOCCUS OP FREIRE. 



Presented to the writer, at the time of his visit to Brazil (1887), by Dr. 

 Domingos Freire, as his yellow-fever germ so-called Cryptococcus xantho- 

 geuicus. 



Morphology. Micrococci, from 0.5 to 0.8 n in diameter, solitary, in pairs, 

 or in irregular agglomerations ; like other staphylococci, groups of four and 

 chains of three or four elements are occasionally formed. 



