366 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



Source. No. of colon-like 



colonies in 1 cc. 



Below Deganwy 

 Off Bodlondeb Point 



55 55 



Channel, opposite Conway 



6 



5 



31 



23 



77 

 63 



Photographs of these Plates are shown in PL III. 



These water analyses show some considerable general 

 pollution of the river and channel. The first series was 

 taken about low water of a spring tide and the pollution 

 at Deganwy is noticeable. There is practically no 

 difference in the bacteriological condition of the water at 

 the Bridge and far down the river. This, I take it, is 

 because of the rapid tidal stream which has thoroughly 

 mixed up the water in the river. In the second analysis, 

 however, we see a considerable difference in the degree of 

 contamination of the river water. The nearer the Bridge 

 the greater is the contamination. These samples were 

 taken about an hour before low water on a neap tide, when 

 the velocity of the stream in the river was not so great as 

 on the previous occasion. 



It would, of course, be desirable to carry these 

 investigations of the pollution of the river water by 

 sewage bacteria much further than has been possible on 

 these occasions. But so far as they go they indicate the 

 pollution of the river water from above. They also show, 

 I think, an undesirable amount of sewage bacteria in the 

 water of the river. 



