19-21.] 



A Shell Factory : for Poultry. 



1033 



A SHELL FACTORY: FOR POULTRY. 



The fame of the English oyster is at least as old as the Roman 

 Empire ; it found an honoured place at Imperial banquets. 

 Juvenal, in his Fourth Satire, writes of the Roman glutton who 

 could " discriminate with nicety at the first taste whether the 

 oysters were Circean natives or bred on the Lucrine rocks or 

 from the Richborough (Rutupiae) beds." Through the centuries 

 intervening, the popularity of the oyster has never waned and 

 to this day such entertainments as the Ovster Feast, celebrated 

 annually at Colchester, are attended by some of the most admir- 

 ing and eloquent lovers of shell-fish. In these circumstances, a 

 threat to the oyster fisheries of Colne and Blackwater and else- 

 where is a threat not only to a thriving industry but to the con- 

 tinuity of a great tradition, and it is an unfortunate fact that 

 the oyster has found a deadly enemy, though one that does not 

 seek deliberately to treat the victim either as a foe or as a source 

 of food. The Slipper Limpet (Crepichda fornieata) lives side 

 by side with the oyster, sometimes even attaching itself to the 

 oyster shell, and competes with it for the food supply. Unfortu- 

 nately too. it multiplies more rapidly than the oyster, to which 

 it bears a relation similar to that between weeds and a neglected 

 crop. Where the limpet does attach itself to the oyster shell — 

 this happens onlv in a minority of cases — the injury is direct. 

 In the presence of such an unwelcome guest the oyster is quite 

 unable to pivot upon its axis and feed in the conventional fashion 

 of its kind, so it has no choice but to die uncomfortably in its 

 bed. A few years ago the mortality from all causes was growing 

 so steadily that (in 1916) a big effort was made to deal with the 

 problem. At West Mersea. in the centre of the Colchester oyster 

 fisheries district, an old barn was set apart as a factory and, 

 under the direction of Dr. H. L. Jameson of the Ministry of 

 Agriculture and Fisheries, a spirited attempt was made to save 

 the threatened industry. A drying machine and a crushing 

 machine were installed, and fishermen who saw their means of 

 livelihood diminishing steadily as the slipper limpet extended its 

 ravages, were invited to enter upon new activities and dredge for 

 their enemy instead of their friend. 



To-day they carry the catch to an uninhabited spit between 

 Tollesbury and W^est Mersea. where it remains for six months, 

 by the end of which time nothing is left but shell. The shells 

 are then brought in wagons to a dump outside the barn whence 

 they are carried to a point where, by means of a series of buckets 



