16 SHELLFISH CONTAMINATION FROM SEWAGE-POLLUTED WATERS. 
summer cottages are springing into existence, the nearest villages 
and cities are rapidly encroaching upon the oyster territory, and 
the community does not concern itself especially about the disposal 
of sewage. Even the oystermen themselves are guilty of contrib- 
uting their quota of contamination by dumping wastes overboard 
from boats or by depositing them in near-by waters through the 
medium of privy vaults located in their shops. These closets are 
almost invariably placed where nature is depended upon to remove 
the accumulating wastes, which are later carried out by the waves to 
some oyster float or bed near by. 
BACTERIOLOGICAL RESULTS ON SHELLFISH AND SEA WATER. 
The following tables show the bacteriological results obtained on 
oysters and clams in the shell and on the sea water covering the beds 
from which they were taken: 
* 
TABLE 1.—Results of the bacteriological examination of shell oysters. 
COLLECTED FROM LOCALITIES REASONABLY FREE FROM EVIDENCE OF POLLUTION. 
Bacteria 
| per cubic | 
centimeter | B. coli per | B. enteri- 
Sample No. | (plain agar | cubic cen- aoe sporo- 
‘incubated | timeter. genes. 
=| 
| 
four days | | 
at 25° C.). | eS eee. 
| 
as 
' 
—_ 
Oo 
(<>) ooocoo°oceoo 
=) ooocoeoe'Te 
Approximate average. -' 4,300 
COLLECTED FROM GROUNDS SHOWING PROBABLE POLLUTION. 
fig Se Rage Eee eee ae 1,500 | 10 | 1 
Dot ee ee eee 10,000 10 10 
Sole a hee Nt ee ee oe | 400 itt 0 
AS ye Spa at See 500 10 1 
5525 ee oe eee eee 5,000 10 10 
Guta oe eer ee | 400 1 0 
(ee ee eee eee 100, 000 10 10 
824 F225 S  eee 7,000 1 1 
O25 ee eee 27,000 1 1 
Os eee a ee ees 17,000 10 10 
iy eee ey yh at Se ea 20,000 10 10 
AD Sets eee eee 8, 000 1 1 
LSS 2138 oe sas hae ee eee 5,000 1 1 
V4 Se ee eS ae eee ee 1,500 1 0 
19822 seer ee 9,000 1 0 
16s cb ive ae eee see eee | 1,000 1 10 
LTS ee Se See 9,000 10 1 
| US. 2 esses eee ee eeeeeeeeesee 4,000 | 10 | 1 
| Approximate average. - 12, 500 | 5.5 | By, 7/ 
. 
