MILK 445 



2. Fill 9 c.c. sterile bouillon into the first, and 9.9 

 c.c. bouillon into each of the three remaining capsules. 



3. Remove i c.c. milk from one of the bottles by 

 means of a sterile pipette and add it to the bouillon in 

 capsule I; mix thoroughly by repeatedly filling and 

 emptying the pipette. 



4. Remove o.i c.c. of the milky bouillon from cap- 

 sule I, add it to the contents of capsule II, and mix as 

 before. 



5. In like manner add o.i c.c. of the contents of 

 capsule II to capsule III; and then o.i c.c. of the con- 

 tents of capsule III to capsule IV. 



Then i c.c. of dilution I contains o.i c.c. milk sample, 



i c.c. of dilution II contains o.ooi c.c. milk sample, 



i c.c. of dilution III contains o.ooooi c.c. milk sample, 

 i c.c. of dilution IV contains o.ooooooi c.c. milk sample. 



6. Melt the gelatine and the agar tubes in boiling 

 water; then transfer to the water-bath and cool them 

 down to 42 C. 



7. Number the gelatine tubes consecutively i to 12. 



8 . Inoculate the tubes with varying quantities of the 

 material as follows : 



To tube No. i add i.o c.c. of the milk sample. 



2 add o. i c.c. of the milk sample. 



3 add i.o c.c. from capsule I. 



4 add o. i c.c. from capsule I. 



5 add i.o c.c. from capsule II 



6 add o. i c.c. from capsule II. 



7 add 0.5 c.c. from capsule III. 



8 add 0.3 c.c. from capsule III. 



9 add 0.2 c.c. from capsule III. 



10 add o. 5 c.c. from capsule IV. 



11 add 0.3 c.c. from capsule IV. 



12 add 0.2 c.c. from capsule IV. 



9. Pour plates from the gelatine tubes; label, and 

 incubate at 20 C. 



10. Liquefy five wort gelatine tubes and to them 

 add i.o c.c. of the milk sample and a similar quantity 

 of the diluted milk from capsules I, II, and III and IV 

 respectively. 



