462 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



conditions. Those in the Bibble channel near the 

 training wall are exposed to pollution by sewage coming 

 down from Preston and Lytham. It seems hardly likely 

 that the influence of the Preston sewage is appreciable — 

 the distance, in space and time, between original dis- 

 charge and ingestion by the shellfish is too great — but 

 the part of the pollution which is of significance is 

 probably that due to the Lytham sewers. But even this 

 is about 2 miles distant from the bed sampled. The 

 results of the analysis of these mussels were certainly 

 bad, bacteriologically ; they were practically the same 

 as those of the Aberdovey mussels, but I should hesitate 

 at assessing these results at their face value, for the 

 reasons indicated above. "Both these Lytham beds," 

 says Dr. Bulstrode, " are not, therefore, free from risks 

 of pollution by sewage. " But, on the other hand, 

 epidemiological evidence of their role in transmitting 

 disease is lacking. 



The case of the St. Anne's bed is entirely different. 

 Here we have mussels which are, some of them, 

 "literally bathed in sewage." The bed is one of a 

 class to which also belong those at Aberdovey and 

 Barmouth, that is, they are in close proximity to sewer 

 outfalls which discharge straight from town drains, 

 without the intermediation of tanks or screening, or 

 treatment of any kind. One has no hesitation in saying, 

 apart from bacteriological results, that they ought to be 

 condemned, or made the objects of some remedial treat- 

 ment. "It must still be regarded as dangerous," says 

 Dr. Bulstrode, speaking of the Aberdovey bed, "to 

 dredge for mussels in the vicinity of an outfall"; and 

 with regard to the Barmouth bed: "It is clear that 

 there is great danger from the consumption of mussels 

 dredged up from the vicinity of the estuary outfall " ; 



