CHAPTER IX. 



T II E M A B I X K A Q U A B I D U . 



Murine and Fresh-water Tanks contrasted — Advantage of Flat-sided Vessels for 

 Marine Aquaria — Kock-pools— Bottom of the Tank — Shell bottom — Kocknork to 

 project above the Surface of the 'Water for the Fiddler Crabs— Introduction of 

 Vegetation — Water — Washing Wants — Procuring Sea 'Water — Cask for holding it 

 — Artificial Sea-Water — Its Manufacture — Seasoning the 'Water. 



As the laws of nature arc fixed and unchangeable, and as 

 they govern the plants and animals living in the ocean 

 as well as those that dwell in ponds and rivers, a ma- 

 rine Aquarium has of course to be established on the 

 same principles as a fresh-water one. The management 

 of the two different kinds of Aquaria will, also to a 

 certain extent, be similar. The only great difference be- 

 tween them consists in the appearance presented by each 

 when fully stocked, for, though the fish may appear 

 similar, the other animals and the plants will be entirely 

 different. They that " go down to the sea " have stranger 

 talcs to tell of its wonders than they who explore the 

 lake, pond or river. In the fresh-water collection wc 

 have not the many-tinted anemones, the brilliant Berpulae, 

 and, then, the Crustacea are, in such a tank, restricted 

 to a few species that arc difficult to keep alive in con- 

 finement ; whilst, in the marine Aquarium, we have the 



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