148 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



depth of two feet, and then the heavy seas reach the bed 

 and roll the Mussels off like a carpet, and I have seen 

 them strewn along the beach at high-water mark as far as 

 Lytham Pier, a distance of four miles, during the same 

 tide. 



Under the refreshment rooms at Southport Pier is a 

 foundation composed of stone on which Mussels strike. 

 They then accumulate mud until their cables, or byssus, 

 reaching down to the stones, get too weak, and they 

 are then washed away. The same thing occurs in 

 the Bock Channel, and on the great scars at Heysham. 



In the case of St. Annes, and doubtless in the other 

 cases also, if the seaward edge of the scar was protected 

 by piles or posts, and the Mussels so rendered less liable 

 to be broken into by the sea, they would then, in all 

 probability, be able to grow to a marketable size. 



The researches of Mons. Viallanes at Arcachon, in the 

 South of France, have proved the power of Mussels in 

 comparison with Oysters to separate food and refuse (sand, 

 &c.) from the water. By his experiments he shows that 

 for one quart of water filtered by a French or native 

 Oyster 18 months old, a Portuguese Oyster of the same 

 age filtered 5J quarts, and a middie-sized Mussel 3 quarts. 

 The excreta respectively were 0*199 gramme, 1*075 

 grammes, and 1*768 grammes per 24 hours. So that in 

 proportion to the numbers covering the same area of 

 ground the Mussel will deposit three times as much 

 material as a Portuguese, and eighteen times as much as 

 a French or native Oyster. 



There is no doubt but that the rate of growth is to a 

 great extent proportional to the foo.l consumed, so that it 

 is clear that the Mussel has a much greater quickness of 

 growth than a native Oyster. 



The accumulation of mud (other conditions being the 



