OYSTERS 465 



towel. Turn a corner of the sterile towel over the 

 upper flat shell to give a firmer grip to the left hand, 

 which holds the shell in position. 



5. With the sterile oyster knife (in the right hand) 

 open the shell and separate the body of the oyster 

 from the inner surface of the upper flat shell. Bend 

 back and separate the flat shell, leaving the body of the 

 oyster in and attached to the concave shell. Avoid 

 spilling any of the liquor. 



(Some dexterity in opening oysters should be 

 acquired before undertaking these experiments). 



6. Cut up the body of the oyster with sterile scissors 

 into small pieces and allow the liquor freed from the 

 body during the process to mix with the liquor previ- 

 ously in the shell. 



7 . Transfer the comminuted oyster and the liquor to 

 the cylinder. 



8. Treat each of the remaining oysters in similar 

 fashion. 



9. Mix the contents of the cylinder thoroughly by 

 stirring with a sterile glass rod. The total volume will 

 amount to about 100 c.c. 



10. Use o.i c.c. of the mixed liquor to inseminate 

 each of a series of three nutrose surface plates. 



11. Inoculate o.i c.c. of the mixed liquor into each 

 of three tubes of litmus milk. 



1 2 . Add sterile distilled water to the contents of the 

 cylinder up to 1000 c.c. and stir thoroughly with a 

 sterile glass rod and allow to settle. The bacterial 

 content of each oyster may be regarded, for all practi- 

 cal purposes, as comprised in 100 c.c. of fluid. 



13. Arrange four glass capsules in a row and number 

 I, II, III, IV. Pipette 9 c.c. sterile distilled water into 

 each. 



14. To capsule No. I add i c.c. of the diluted liquor, 

 etc. from the cylinder, and mix thoroughly. To cap- 

 sule II add i c.c. of dilution in capsule I and mix thor- 



3 



