53 



from these silent unobtrusive enemies. As may be 

 readily understood the chief danger from this source 

 arises during the period the collector tiles are stacked in 

 the ruches. At that time the water is full of the em- 

 bryos and larvae of a host of creatures all as keen to find 

 clean firm foothold as are the swimming spat of the 

 oyster. Every one that attaches to a collector reduces 

 the space available for oyster settlement and as these in- 

 truders increase in size and appetite they compete with 

 the young oysters for the current-brought food — a 

 competition which if not checked results in stunting 

 and virtual arrest of growth. Mussels and sea-squirts 

 (ascidians) are the most troublesome of these greedy and 

 unwelcome creatures but whereas the latter settle chiefly 

 on the surface of the tiles, the former cluster by preference 

 on the wooden frames of the ruches and on the exposed 

 edges and ends of the tiles, positions which enable them 

 to intercept the bulk of the food matter before it flows 

 through the stack of tiles. Always do mussels select the 

 positions which give them the vantage of being able to 

 filter out and seize the best of the food brought by the 

 tides and currents. Apart from the collectors their 

 favourite settlement is upon the fences that surround 

 the parks and the faggot bunds of the claires. A wall of 

 greedy mouths encircles every park, impoverishing the 

 waters and robbing the oysters even of their fair share of 

 the common food supply. In some years the abundance 

 of mussels has entailed most serious losses upon the 

 parkers, for besides causing stunting of growth an 

 enormous abundance may so prejudicially affect the spai- 

 fall as to produce actual scarcity. It happens that the 

 mussels spawn rather earlier than the oysters so while 

 the latter are vet in the swimming stage the mussels 

 have settled down and are busy filtering out the little 

 particles of food essential to" the well-being of the 

 oysters. 



The lug-worm (Arenico/a) gives trouble to the parker 

 in quite a different way. This worm has the habit of 

 burrowing in muddy sand, feeding on the decaying organic 



