SEA-FISHERIES LABORATORY. 



347 



As before, a number of the colon-like colonies from 

 the primary plates made from the Outer Skear mussels 

 were subcultured. The results are given below in detail. 

 It is evident that colonies 8, 9, 9, 10, 10, are not those of 

 B. coli, while there are other four in which motility was 

 not observed. Four colonies are those of typical B. coli. 

 This is a lower proportion than was observed in the case 

 of mussels taken from the shears higher up the Channel, 

 and therefore nearer to the sewer outfalls. It is what 

 one might expect to find. The contamination of the 

 outer Heysham Skears is less than that of Baiting Knot 

 and Ring-Hole. By the time that the sewage reaches the 

 Heysham Skears it has become so greatly diluted that 

 there is a much less chance of sewage bacteria being 

 ingested by the shellfish. The percentage of microbes 

 indubitably identified as B. coli is also less, an indication 

 that the micro-organism undergoes some change as a 

 result of its sojourn in sea-water, or perhaps perishes 

 altogether. 



2nd Analysis. 

 Results of Tertiary Subcultures from Primary 

 Plates. 



Mussel, q 1 ^®" Glucose. 



Lactose. 



Mannose. 



Cane 

 Sugar. 



Milk. Motility. 



6 



.. ag .. 



ag • 



• ag 



•• ag .. 



d . 



.. a c 



. + 



6 



.. ag .. 



ag • 



• ag 



.. ag .. 



d . 



.. a c . 



. + 



7 



•• ag .. 



ag . 



. ag 



.. ag .. 



o . 



.. a c . 



. + 



7 



.. ag .. 



ag . 



• ag 



.. ag .. 



. 



.. a c . 



— 



8 



o 







. o 



o 



o . 



.. a c 



. + 



8 



.. ag .. 



ag . 



• ag 



.. ag .. 



o . 



.. a c . 



. — 



8 



.. ag .. 



a g • 



. ag 



.. ag .. 



o . 



.. a c . 



. + 



8 



•• ag .. 



ag • 



. ag 



.. ag .. 



. 



.. a c . 



. — 



9 



•• ag .. 



ag • 



a 



.. ag .. 



. 



.. a c . 



. + 



9 



a 



a 



a 



a 



a . 



o 



— 



10 



a 



a 



a 



o 



o . 



.. a c . 



. + 



IO 



a 



a 



o 







o . 







. + 



