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 previously 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 0.1 c.c. of the mixed liquor to inseminate each of a series of three nutrose surface plates. 11. Inoculate 0.1 c.c. of the mixed liquor into each of three tubes of litmus milk. 12. 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 practical 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 1 c.c. of the diluted liquor, etc. from the cylinder, and mix thoroughly. To capsule II add 1 c.c. of dilution in capsule I and mix thoroughly. Carry over 1 c.c. of fluid from capsule II to capsule III, afterwards adding 1 c.c. of fluid from capsule III to capsule IV. 15. Label tubes of bile salt broth and inoculate with the following amounts of diluted oysters: No. 6 with 10 c.c. cylinder fluid = 0.1 oyster. No. 5 with 1 c.c. cylinder fluid = 0.01 oyster. No. 4 with 1 c.c. capsule I fluid = 0.001 oyster. No. 3 with 1 c.c. capsule II fluid = 0.0001 oyster. No. 2 with 1 c.c. capsule III fluid = 0.00001 oyster. No. 1 with 1 c.c. capsule IV fluid = 0.000001 oyster. 16. Transfer 100 c.c. cylinder fluid (= 1 oyster) to an Erlenmeyer flask and add 50 c.c. double strength bile salt broth, and label 7. 17. Duplicate all the above indicated cultures. 18. Put up the tube cultures in Buchner's tubes and incubate anaerobically at 42° C. If growth occurs in tube 1 the organism finally isolated, e. g., B. coli, must have been present to the extent of one million per oyster. 19. Complete the examination for members of the Coli-typhoid group and sewage streptococci, as directed under Water Examination, page 429 (steps 11-21). 20. Inoculate a series of 6 tubes of litmus milk with quantities of the material similar to those indicated in step 15; heat to 80° C. for ten minutes, and incubate under anaerobic conditions at 37° C. Examine for the presence of B. enteritidis sporogenes as directed under Water Examination, page 438 (steps 7-10). EXAMINATION OF SEWAGE AND SEWAGE EFFLUENTS. Quantitative.-- _Collection of the Sample._--As only small quantities of material are needed, the samples should be collected in a manner similar to that described under water for quantitative examination and transmitted in the ice apparatus used in packing those samples.