58 MUSSEL CULTURE 



this effect where much fresh water remains amongst 

 the mussels. 



Favourable Conditions and Treatment of Scalps. 



The presence oi fresh water in the neighbour- 

 hood of scalps is considered by some to be dis- 

 advantageous, and it is possible to point to ' deep 

 water beds ' away from much influence of fresh 

 water, which carry uniformly large-sized shell-fish. 

 But, as we have already shown, the most natural 

 habitat of the mussel is in estuaries where a con- 

 siderable proportion of fresh water is present, 

 where at the same time each rising tide carries up 

 salt water. The condition might be described as 

 a constantly varying one, — at one time fresher, at 

 another time Salter. The average specific gravity 

 could only be determined at any one naturally 

 fruitful bed, by a long series of observations em- 

 bracing all extremes. I have no doubt, that if 

 this were done at a number of places, we could 

 eventually determine without much difficulty what 

 the most beneficial water conditions are ; but 

 at the same time we should probably also find 

 that the mussel could thrive perfectly by adapting 

 itself to the particular conditions of different 

 localities. An extreme of salt water tends to 



