Aqiiiculture. 183 



have been gradually rising for the last ten 

 years. This is, no doubt, owing to the exten- 

 sive works by which many swamps and marshy 

 places have been freed from surplus water and 

 drained, so as to become better fitted for 

 pasturage. This increase in the quantity of 

 water in the lake, should it continue, will 

 inevitably cause its waters to overflow into its 

 natural outlet in the Barwon river. Hitherto 

 the evaporation over its large surface has 

 balanced the drainage flowing into it, so that 

 no overflow bas occurred; but should its waters 

 rise so as to overflow every season, the amount 

 of salt carried away would necessarily cause 

 the water of the lake to become fresher every 

 year, and it would be interesting to know 

 whether the sea fish introduced there could 

 adapt themselves to the gradual change from 

 salt to fresh water, which would then take 

 place. 



The oyster-fisheries of Yictoria, that were 

 once productive, have now failed almost en- 

 tirely, and that colony is dependent upon other 

 places for supplies of that delicious bivalve. 

 Why should not scientific culture restore the 

 productiveness of the old oyster-beds, and with 



