50 THOMPSON YATES LABORATORIES REPORT 
in the same percentage — 0.5 — glucose was most favourable to B. c. c. ; but that 1 p.c. 
of lactose gave results equal to 0.5 p.c. glucose. It was doubtful whether mannite 
had an equal inhibitory effect upon other organisms. - 
As nitrates, chlorides, and phosphates seemed unfavourable, it was thought that 
possibly Liebig's Extract might be of use in giving the extra amount of nourishment 
apparently required. So garden earth and road sweepings were thoroughly shaken up 
with tap water, and the mixture plated in 
I. B. s. 0.5 p.c, peptone 2 p.c, lactose 0.5 p.c, agar 1.5 p.c. 
II. B. s. 0.5 p.c, peptone 2 p.c, lactose 0*5 p.c, agar 1.5 p.c, Liebig 0.1 p.c. 
Nutrient agar being used as a control. 
The control plate was covered with all kinds of colonies. 
I. The plates appear to contain only one kind of organism. On one of 
them there were 12 surface colonies. Eleven of these were subcultured in broth, 
and afterwards in milk, glucose jelly, and potato. 
Broth 
Milk 
Glucose Jelly 
Potato 
Inrlol 
General 
turbidity 
Acid and 
clotting 
Profuse gas 
No liquefaction 
Moist, grey 
growth. P.D. 
2. 
Actively motile. Short bac. 
Yellowish P.D. 
+ 
3- 
+ 
4- 
Motile 
+ 
5- 
Actively motile 
+ 
6. 
Motile „ 
+ 
+ 
8. 
Actively motile ,, 
Almost invisible 
+ 
9- 
Moist, grey. P.D. 
+ 
10. 
Yellowish „ 
+ 
1 1 . 
+ 
P.D. = discolouration of potato. 
II. The plates appear to be a pure culture. The numbers are practically the 
same as in I. There were 1 1 surface colonies on one plate. These were all sub- 
cultured in broth, and later in milk, glucose jelly, and potato. 
