SEA-FISHEEIES LABOEATOEY. 253 



sterile water. One cc. of this was then inoculated in 

 99 ce. of sterile water, and 1 cc. of this latter dilution was 

 again inoculated in other 99 cc. of sterile water. By 

 repeating this process four liquids were obtained : — ■ 

 Dilution I. — 1 cc. contained i^th part of a mussel. 



TT i 



>> M - L ' »J " 1000" " 



TTT _ i 



>> J--LJ-. »3 »' lOOOO" " 



>j -LV. ,, ,, iooooo " '' 



Then 1 cc. from each dilution was inoculated in about 

 10 cc. of neutral-red agar liquid at a temperature of 

 12° C.j and the latted media were then poured into Petri 

 dishes and incubated. At the same time 1 cc. of each 

 dilution was inoculated in milk tubes, and the latter were 

 incubated anaerobic-ally as before. 



The results were that the first plate (Dilution I.J 

 showed 12 colon-like colonies, some of which proved on 

 further sub-culture to be those of B. coll. The other 

 plates were sterile so far as this microbe was concerned. 

 1 cc. of Dilutions I. and II. gave the enteritidis test in the 

 typical manner. 



Therefore, B. coli was present in T ^opart of a mussel 

 from the Bock Ferry bed, and B. enteritidis sporogenes 

 was present in ^m^ part. 



The Wallasey Mussel Bed. 



It was thought advisable to examine this bed also for 

 evidences of sewage pollution, though I did not expect 

 to find such so marked as in those beds in the estuary 

 itself. Indeed, from its open and exposed situation it 

 was thought probable that pollution by sewage would not 

 be evident here. The bed is an important one; it is of 

 large extent, and at times it is the area of a considerable 

 fishery. Its situation is shown on the chart on next page. 

 It lies far out from shore; extending from near the N.W. 



