228 MARINE VIVARIA, 



MARINE VIVARIA. 



One prominent object that I had in view in coming 

 to the coast was the prosecution of a cherished scheme 

 for the conservation of marine animals and plants in 

 a living state. 



For several years past I have been paying attention 

 to our native Rotifera, and in the course of this study 

 had kept fresh water in glass vases unchanged from 

 year to year, yet perfectly pure and sweet and fit for 

 the support of animal life, by means of the aquatic 

 plants, such as Vallisneria, Myriophijllum, Nitella 

 and Char a (but particularly the former two), which 

 were growing in it, Not only did the Infusoria and 

 Rotifera breed and multiply in successive generations 

 in these unchanged vessels, but Entomostraca, Plan- 

 arice, Naicles and other Annelides, and Hydrce, con- 

 tinued their respective races ; and the young of our 

 river fishes were able to maintain life for some weeks 

 in an apparently healthy state, though (perhaps from 

 causes unconnected with the purity of the water) I 

 was not able to preserve these long. 



The possibility of similar results being obtained 

 with sea- water had suggested itself to my mind, and 

 the subject of growing the marine Algse had become 

 a favourite musing, though my residence in London 

 precluded any opportunity of carrying out my project. 

 My notion was that as plants in a healthy state are 

 known to give out oxygen under the stimulus of light^ 

 and to assimilate carbon, and animals on the other 

 hand consume oxygen and throw ofi" carbonic acid^ 

 the balance between the two might be ascertained by 



