122 THE AUSTRALIAN OYSTER. 



floated into these places. If this opinion is attempted to be relied upon, and 

 acted on practically, I predict that very serious disappointment will follow. 

 I believe that our fine mud oyster, so much ignored, does exist outside the 

 heads of our harbours, just as they do in Europe, in America, and in New 

 Zealand, and even in Victoria, South Australia, and elsewhere. But what 

 use is it discovering their whereabouts as long as this splendid oyster is 

 neglected and ignored ? 



The spawn of the oyster similar to our mud oyster in Europe and in 

 America is not a surface floating spawn ; and, from the experiments I have 

 made with ova taken from our mud oyster, I am satisfied also that it is not a 

 surface swimming spawn. Let me mention that there was a time when this 

 oyster was so abundant (as is evident from the remains of its shells in the 

 old camp-ovens of the native tribes of this coast, and from the deposit along 

 our muddy shores) that it was the only oyster which the natives thought 

 worthy of carrying to their haunts to cook. If we may judge from these 

 evidences, they must have existed in enormous numbers, as abundant as 

 they are found at the present day in most of the undisturbed lakes between 

 Shoalhaven and Eden, where, in one lake, I am informed, they exist in 

 hundreds of tons. If this mud oyster exists outside our harbours, and 

 produces its kind in our lakes and rivers, it will be said why should there 

 not be beds of our drift oysters also outside our hai'bours, the spat of which, 

 like the spat of the mud oyster, would be carried into our estuaries, and 

 come to maturity on their own selected ground ? All I can say is that, 

 having endeavoured to examine the natiire of the spawn of the drift oyster, 

 I have reason to believe that its ova are heavy and unsuited for being floated 

 far and wide, and that it adheres to any object close to which it was extruded 

 from the ripe oyster. JNTotice how genuine drift oysters when taken from 

 their natural bed are adhering to small fragments of shell or gravel which 

 is found on the bed. Such oysters are always found on circumscribed beds. 

 You do not find them generally disseminated over the bottom of the estuary, 

 where they grow. If a pile be driven down on a bed of these oysters you 

 will not find the young adhering to it from the surface of the bed to the 

 point above high and low water mark. But at the latter point you will find 

 not drift oysters adhering, but oysters similar to our common rock oysters. 

 Again, if this oyster were the same species as our common rock oyster we 

 would naturally expect to find it growing to the whole rocky surface of the 

 bank where it exists from the bottom up to the zone, where we find our rock 

 oysters exist. But this is not the case. There is an intervening gap 

 between these two kinds free of oysters altogether. 



Until recently I have been under the impression that our drift oyster 

 did not adhere along its whole under surface to fixed objects such as rocks. 

 But in this I now feel sure that I was mistaken ; for divers have brought up 

 from 70 to 80 feet deep, and even from greater depths, undoubted specimens 

 of our drift oyster adhering throughout almost the whole of the under 

 surface, from localities where beds of drift oysters were once abundant in a 

 loose state, but which had, by dredging, almost all disappeared ; these 

 adherent oysters had escaped the dredge. I think, therefore, that sufiicient 

 attention has not been devoted to the replenishment of our natural beds 

 with their own kind. 



I have never myself succeeded in making rock oysters grow or live beyond 

 a very limited period by sinking them in cages many feet below where they 

 are naturally found. Recently attempts have been made to establish oysters 

 on what were known as old drift oyster-beds, by depositing on them rock 



