230 TRANSACTIONS L1YEKPOOL BIOLOGICAL SOCIETY. 



after year, and often when the fisherman is looking 

 forward to a profitable fishery his anticipations are ruth- 

 lessly shattered in a .single night. A bed that twenty- 

 four hours previously may have been populated by tons 

 of marketable mussels of considerable money value 

 becomes changed into a clean bank with a hard bottom. 

 Then the process of re-formation of the bed begins, and 

 in time the bank becomes again covered with mussels. 



When the Heysham Shears were visited again, about 

 two months after the transplanting, it was found that the 

 removal of nearly 350 tons resulted in very little appre- 

 ciable change in the appearance of the beds. The clearings 

 that had been made in April had certainly been more or 

 less covered again by the mussels spreading out, but the 

 overcrowding was just as bad. The proportion of 

 minimum legal sized mussels had advanced from 18 per 

 cent, to nearly 25 per cent., but in many places, however, 

 the stones, zoophytes and mussels themselves had a 

 covering of spat from the spawning that had taken place 

 in the interval, and four generations could be 

 distinguished. 



We conclude by giving a summary of the results 

 obtained : — 



Amount expended: 1903, £50; 1904, £50; 1903, 



£75. 

 Estimated profit: 1903, £500; 1904, £500; 1905, 



£800. 



A sample of the "Blue nebs" transplanted at Wardley's in 1905, 

 has been sent to Piel for examination, within the last few days, by 

 Captain Wright. Careful measurements of the new growth have been 

 made, and it is found that the average increase during a period of ten 

 months is thirteen-sixteenths of an inch. The following is the amount 

 of new shell, in sixteenths of an inch, added in each of eight mussels 

 during the time stated. 

 No. 1. No. 2. No. 3. No. 4. No. 5. No. G. No. 7. No. 8. 



i :, 



14 



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18 



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