OYSTEE-CULTUEE IN AUSTllALASIA. 571 



or to get covered up by sedimentary deposits, and here the 

 spht-paling collectors, on which the attachment-surface for 

 the spat is raised some inches above the surface of the 

 bottom, has a distinct advantage. Branches of certain trees, 

 utilised after the manner of the French fascines, are also ex- 

 ceedingly effective spat-collectors in some localities. Dis- 

 crimination must, however, be used in the choice of the timber; 

 the majority of varieties, and in Australia the many species of 

 gum-trees or Eucalyptus more particularly, being altogether 

 unsuitable for the purpose, and apparently distasteful to the 

 young oyster on account of the resinous secretions they con- 

 tain. Different varieties of pine-trees, and the Casuarinas, or 

 "bull-oak" and " sheoak," as they are locally termed, have been 

 found by personal experience to yield the most favourable re- 

 sults. The ^YOod, or, more correctly, the aerial roots and shoots. 

 of several varieties of mangroves, notably Bhizoplwra and A']gi- 

 ceras, form, as is well known, natural attachments to the young 

 of the rock-oyster, giving rise to the truism, at first regarded 

 as a mere traveller's tale, that Australian oysters grew upon 

 trees. One little species, as described in the earlier portion 

 of this discourse, outstripping Ostrea glomerata in ambition, 

 has actually established itself upon the leaves of the favoured 

 mangrove. 



The Chinese, with the patience characteristic of their race, 

 have propagated their oyster, which closely resembles Ostrea 

 edulis, for centuries in great abundance by means of oyster- 

 shells inserted into the cleft ends of pieces of bamboo, which 

 are then stuck upright in the mud, the shells being raised a 

 few inches above the surface. The spat soon collects on these 

 shells, and when of sufficient size is removed and distributed 

 over the fattening-beds. A similar plan would, it may be anti- 

 cipated, prove equally successful if applied to . the Australian 

 rock-oyster. Cemented tiles, utilised so extensively in asso- 

 ciation with the French fisheries, are scarcely likely to find 

 favour with Australian oyster-growers on account of their 

 costliness. In France even their standard price is £2 per 

 thousand, and out hero they could scarcely be produced at 

 less than double that sum. Split palings, which give twice 

 the surface-area for the attachment of the spat, and, at 

 the most, at only one-quarter of the cost, cannot fail to 

 recommend themselves as a matter of pure economy. One 

 special advantage possessed by this form of collector, but 

 not previously referred to, is the shelter from the sun's 

 heat they afford to the young brood when left high and dry 

 by tha receding tide. Thousands, or, more correctly, mil- 

 lions, of the brood of the Australian rock-oyster are destroyed 

 annually through exposure to the overpowering heat of the sub- 

 tropical sun in the early days of their attachment to exposed 



