18 



In lactose agar the growth exceeded that on plain and glucose 

 a^ar and was more waxy lookmg. In shake cultures there were 

 numerous lenticular gas bubbles. In 48 hours there was an increase 

 in the number of gas bubbles, and the agar was rent across the tube. 

 In three days the clear space between the rents was wider, otherwise 

 no change. 



In glucose agar the growth w^as about the same as on plain agar, 

 if anything, slightly heavier. Shake cultures contained small gas 

 bubbles all through agar. No further change after three days growth 



In maltose agar growth was very abundant, moist and shiny. 

 There was more tendency to spread. Growth exceeded that on plain 

 agar. 



In shake cultures very few gas bubbles appeai^ed in 24 hours. 

 In 48 hours, a few more bubbles made their appearance and no 

 further change took place after the third day. 



Neutral red agar (with 2 per cent, glucose at 28° C.) In 24 

 hours, there was no change in color, a white growth along the line of 

 puncture and a moist white growth on the surface. A few gas 

 bubbles were present. In 48 hours, there was no change in color but 

 more orowth. On the sixth dav, the color was lilac violet and no 

 further change occurred. (20 days.) 



Milh. A number of milk tubes + 1.5 per cent., inoculated with 1 

 oese of a fresh bouillon culture and held at 25° C shewed no change 

 for 24 hours. In two days the milk was thicker but did not coagulate 

 until the third day. The curd was soft and even, but thicker at the 

 bottom of the tube. On the fourth day, the curd shrunk and on 

 shaking, the whey separated out. The curd was flaky with a few 

 gas bubbles in it. On the fifth day, the whey on the surface was 

 clear and remained so. In eight days, the curd shrunk and occupied 

 one-third the depth of the medium. No further change took place. 

 The vp-hey from milk cultures tested for proteolytic enzymes, by 

 means of the caustic potash and copper sulphate test, gave a violet 

 color indicating the presence of peptones. Another portion of whey 

 was mixed with ammonium sulphate to precipitate the proteids, and 

 the filtrate from this precipitate was also tested in the same way, and 

 with the same results. 



The odour of milk cultuies after heating was agreeable, 

 resemblino; cheese curd. No odour could be noticed in the cold 

 cultures. 



