23 



scar vhich only settled down in April, 1895, had reached 

 in the majority of cases to nearly three-quarters of an inch 

 in about a period of five months, those on the inner scar 

 deposited at the same time had scarcely attained to 

 one-quarter of an inch in length when the examination 

 was made. The Mussels on the outer scar are very 

 numerous being so closely packed together in some places 

 that there appears to be scarcely any space left for further 

 growth of the shell-fish, but as they have now no firm 

 attachment owing to their having to keep moving as the 

 mud accumulates, they are liable to be washed off by any 

 heavy sea from the southward, and carried off into the 

 deeper water outside the scar from whence they can only 

 be obtained by raking. The shells are quite clean and free 

 from barnacles. 



It is difficult to explain why the Mussels on the outer 

 scar should grow so much faster than those on the inner 

 scar as the conditions of the bottom must have been 

 much alike in structure and wealth of food supply before 

 the spat settled down. Possibly the rapid growth of the 

 Mussels on this scar may be due to the large quantities 

 of fresh water that pass over it when the tide is out, little 

 or none of which appears to reach the Mussels on the 

 inner scar. This water will bring down diatomaceous and 

 other material collected on its passage across the shore, 

 which will be deposited when it comes into contact with 

 the sea and will accumulate in considerable quantities 

 just at low-water mark, forming a splendid rearing ground 

 for the microfauna that forms the principle source of food 

 of the Mussel. Whether this be the true explanation or 

 not, the rapid growth of the Mussels on the outer scar is 

 without doubt due to some important cause which does 

 not affect the inner scar, and which can only be found 

 out by further investigation. 



