SOURCES OF CONTAMINATION. 35 
the minced meat and body contents of the same oysters. The results 
further show that the liquor contained eight times as many B. coli 
per cubic centimeter as the minced meat. 
TaBLE 11.—The relative number of organisms in oyster and ein meat and liquor samples 
on plain nutrient and on saltless agar at 25° and 87° C, 
Organisms per cubic centimeter after | Approximate aver- 
four days’ incubation. age. 
emuple Description of sample. <= a er 
: Plainagar| Saltless |Plainagar| Saltless 25° C 37° C 
PEN, ener AsO OH! BE (CE. Veerireiy(e(Ca) = ‘: 
hoeee oaea Oysterimeatecceesssastemes ce 23, 000 12, 000 7, 000 21, 000 17, 500 14, 000 
eats 3 ak Oystenliquorceesec-cee seem. - 230,000 | 190,000 60, 000 43,000 | 210, 000 51, 500 
Fae Oystersmeat=as sss ne 70, 000 41,000 26, 000 13, 000 55, 500 19, 500 
ACO ae: Oysterliquors. -2.225. 52-52 5--- 150, 000 60, 000 70, 000 14,000 | 105,000 42, 000 
Steere Clam meaty J eijacee.- as-is 7, 000 1,000 3, 000 1, 000 4, 000 2,000 
Geese eee: Clammuliquor2e a2 en ee eeese ee 21, 000 6, 000 2, 000 3, 000 13, 500 2, 500 
(oaeeReee Clamumeat 2.2. stces ee oes 110,000 | 100,000 20, 000 11,000 | 105,000 15, 500 
Ser Buen ee ClamiMiquor.22.22. 2235.4 0...4- 180,000 | 170,000 70, 000 85,000 | 175,000 77, 500 
Approximate average.........- 99,000 | 72,500 32, 000 24, 000 85, 700 28, 000 
Approximate average of oyster meat at both temperatures......--- 26,000 organisms per cubic centimeter. 
Approximate average of oyster liqnor at both temperatures... ...-- 102,000 organisms per cubic centimeter. 
Approximate average of clam meat at both temperatures.........-- 31,000 organisms per cubic centimeter. 
Approximate average of clam liquor at both temperatures........-- 67,000 organisms per cubic centimeter. 
The general averages show nearly three times as many organisms 
per given volume for the liquor of oysters and of clams as for the 
same volume of meat substance. This explains the fact claimed by 
practical oystermen that the liquor spoils before the meat of shellfish. 
CHARACTER OF CONTAINERS. 
The proper cleansing and sterilization of utensils and containers is 
essential to insure freedom from contamination. Single-shipment 
cans properly handled are less lable to harbor objectionable bacteria 
than are those packages used for more than one shipment; however, 
there is no objection to using the latter if they are free from bacteria. 
Cans are often returned to the shipper in very bad condition, and 
unless well scrubbed and sterilized they may become a source of 
danger. By the use of single-shipment packages and a plentiful 
supply of boiling water there should be no difficulty experienced 
from unclean vessels. After cleansing and sterilization cans should 
be inverted or otherwise protected against the entrance of dust, 
which nullifies the good done by sterilization. 
Progressive oystermen now agree that the best method of shipping 
oysters is in sealed packages with no ice in contact with the goods. 
This method prevents contamination from impure ice and protects 
the oysters in a better manner during shipment than did the old 
style of tub with ice in contact. The series of shipping experiments 
made fully demonstrated the superiority of the more modern 
method. 
