41 8 APPENDIX. 



c. The colonies are red. 



(1) Micrococcus cinnabareus forms cinnabar red drops, grows very 

 slowly, only just visible at the end of four clays in the deeper gelatine, and 

 colonies are very small on the surface ; at the end of eight days appear 

 as small wax-like drops on the surface of the gelatine, these gradually 

 deepen in colour ; the deeper cultivations along the needle track remain 

 white ; on plate cultivations superficial colonies when seen magnified by a 

 lens, are light brown, rounded with somewhat irregular outline, and slightly 

 nodulated surface ; margins transparent. 



(2) Micrococcus roseus, a rose-coloured growth, flourishes luxuriantly on 

 the surface of gelatine and at the ordinary temperature ; somewhat raised, 

 especially at the margins ; moist and granular with distinct rosy red colour ; 

 arranged as diplococci with a broad division between the two halves, I 

 to i.5/i in diameter. 



(3) Pink Torula (not a micrococcus, but frequently met with). A coral 

 pink mass, growing freely on the surface of gelatine. Small white or 

 grey points along the needle track. On bread paste grows as a rose-coloured 

 succulent film. It consists of rounded or slightly oval cells 5 to 8/t in 

 diameter ; these contain pigment of delicate yellow colour, under micro- 

 scope, pink only in mass. 



D. The colonies are black. 



(i) Black Torula (not a micrococcus, but sometimes met with in air). 

 Grows on gelatine as a black heaped -up mass. Along the track of the needle 

 it forms small black nodules. On potato and bread paste grows as a dull 

 sooty crust with a dry slightly furrowed surface. In milk it forms a black 

 crust, with a dusky grey tint on the upper surface. The milk itself becomes 

 of a muddy colour from an invasion of the deeper layers by colonies of the 

 organism. Under the microscope is like the Pink Torula, but with a dark 

 brown pigment. 



II. The gelatine is liquefied. 



A. The colonies are white. 



B. The colonies are yellow, see p. 419. 



A. The colonies are white. 



(1) Staphylococcus pyogenes albus. Grows rapidly in plate cultivations; 

 colonies seen under lens are dark in the centre, with smooth borders ; 

 liquefy the gelatine on the second or third day, forming a little clear cup, 

 with a white mass at the bottom ; liquefying centres gradually run together. 

 Along track of needle white mass is formed ; liquefaction commences at 

 surface and extends along the whole track ; at the bottom of the liquefied 

 gelatine is a greyish or white deposit ; a micrococcus .8 to .9^ in diameter ; 

 occurs as irregular masses, diplococci, tetrads or short chains ; is fatal in 

 large doses to mice, guinea-pigs and rabbits, if injected into the veins or 

 into the peritoneal cavity, otherwise usually forms abscesses ; appears to be 

 especially associated with suppuration, pyaemia, ulcerative endocarditis, 

 osteo-myelitis and similar diseases ; it is found in pus, necrotic tissues and 

 in capillary vessels of internal organs. 



(2) Micrococcus urea liquefaciens. In plate cultivations forms small white 

 points, somewhat opalescent with well-defined margins which appear in two 

 days ; grows more rapidly near the surface ; surface granular, and as the 



