OYSTERS AND OYSTER FISHERIES OF QUEENSLAND. 271 



the same extent by Hoods from the tributary rivers, from the effects of whicii they speedily 

 recover. 



It is pertinent to mention here that the fears which have been expressed in some quarters 

 lest the disease under notice should be introduced with the worm from New South Wales are, in 

 the author's opinion, altogether groundless. As a matter of fact, Leucodore is ah-eady in Moreton 

 Bay ; it is of cosmopolitan distributi<jn, and has been obtained by the author among the coral- 

 reefs as far north as Torres Strait. So long as the oyster-banks of Queensland are maintained in 

 a clean and healthy state, the worm is not likely to invade them. So soon, however, as these 

 become choked with foul mud and sedimentary deposits, the conditions will be made favourable for 

 the advent of the worm ; and it may most assuredly be expected. 



There are one or two directions in which the productive oyster fisheries of Queensland are 

 threatened with injury, and to which it is desirable that attention should be paid. Under existing 

 regulations, what are known as the Government or public oyster reserves are supposed to be 

 retained as breeding centres for the express benefit of the general public, who are permitted to 

 help themselves, without restriction, to such oysters as they can consume on the ground, but are 

 prohibited from carrying them away. This privelege, however, has been abused to such an 

 extent, that on many of the most extensive of these preserves the oysters have been completely 

 stripped, and carried off in a wholesale manner. It is, in the author's opinion, essential, for 

 the continued prosperity of the 03'ster fisheries of this colony, that judiciously selected areas should 

 be strictl}' and permanently reserved as nursery or breeding centres, for keeping up the supply 

 of spat. Ha\'ing regard, also, to the extent that many of the leased grounds and banks are denuded 

 of their oyster crops, without compunction or consideration of future cultivators, it is also highly 

 desirable that a clause should be included in the leases granted, requiring the continual reservation 

 on the ground, or bank, of a certain proportion of breeding oysters, or, at all events, prohibiting 

 their entire removal. With such suggested breeding reserves, efficiently maintained, the Queens- 

 land oyster fisheries would be well insured against all risk of the injuiy through over-depletion 

 tiiat has befallen those of certain of the more southern colonies. At the same time, the foundation 

 would be laid for the development of this important industry, on a more extensive scale than has 

 hitherto been attempted, for which there is a wide field open, more particularly in the direction 

 of canning, and other preserving processes, for the export market. 



THE EMBRYOLOGY OF THE QUEENSLAND COMMERCIAL OYSTER, 



OSTREA GLOMERATA. 



Considerable uncertainty having up to a recent date prevailed concerning the embryological 

 phenomena of the ordinary rock oyster of Queensland and New South Wales, the author 

 devoted some time in the year 1890 to the investigation of this subject. The results of this 

 enquiry were embodied in a paper communicated to the Royal Society of Queensland in 

 February of that year, and from it the following account has been epitomised : — 



