5? 



more open to the influence of flood water than those 

 at the seaward anoie of the basin. No remedv other 

 than the removal of the cause is practicable, so when a 

 parker finds his losses are frequent and excessive the 

 only alternative is to abandon his concession and take 

 another in a more favourably situated location. 



The converse of the condition which eventuates in 

 doucain is that where the water becomes excessively 

 saline and of a density abnormally above that of ordinary 

 sea water. As the other extreme produces disease so also 

 does this. At Arcachon it is occasionally experienced on 

 the parks most distant from the sea in seasons of excep- 

 tional drought. Fortunately this condition is of very rare 

 occurrence and quite exceptional. The tissues of oysters 

 subjected to a sojourn in extremely saline waters shrink 

 greatly and undergo the same desiccating process that 

 fish do in course of salting or brining. If eaten in this 

 state the oyster is tough and indigestible. 



Typhus and chambrage are diseases due to the 

 presence of an undue amount of fine mud in suspension 

 in the water. Parks with soft muddy bottom are liable 

 to this as the daily operations in the park disturb the 

 surface and when the tide flows over it the lio-ht mud 

 rises and passes to the gills of the oysters, so interfering 

 with nutrition. Typhus is in fact a starvation disease 

 induced by a great preponderance of non-digestible 

 inorganic particles over those of food value in the 

 material ingested. Chambrage is the name given to an 

 ailment which affects sections of the shell-secreting 

 surface of the mantle — an inflammation apparently. Its 

 visible result is the formation within the shell substance 

 of a cavity filled with malodorous putrescent fluid. 



Much more serious is disease of the adductor muscle, 

 known erroneously at Arcachon as maladie du pied. 

 In some years, notably iSyy-yS, it has assumed an 

 epidemic form causing losses of considerable moment to 

 the parkers. It is a fungoid disease affecting the muscle 

 fibres of the great cylindrical adductor muscle which lies 



