RIVER GARDENS; 



which they cover the surface of still waters. In the 

 Vivarium the Duckweeds are found of great advan- 

 tage, from their peculiar habit of growth, which 

 affords a natural screen to the animals below, when 

 the sun is too powerful ; and Dr Lankester tells 

 us, in his instructive little work, that these plants 

 harbour a number of minute creatures, among 

 which the microscopist may hunt for some of his 

 most valued game, which at the same time pro- 

 vides food for the fish and other inmates of the 

 Aquarium. All that is necessary to establish a 

 Duckweed screen is to remove a small portion of it 

 from the surface of some neighbouring pond, when it 

 requires no other replanting than merely throwing it 

 into the Aquarium, where, being strictly a floating 

 plant, it soon establishes itself and spreads rapidly. 

 The loose pieces should, however, be picked out, as it 

 is only in a mass that it produces a pleasing effect. 

 The Cape Aponogeton is one of the most desir- 

 able plants for the Aquarium, as it continues flower- 

 ing nearly all the year round, and the flowers 

 themselves, besides being very pretty, are sweet- 

 scented. It is quite hardy, and grows with great 

 luxuriance in our open ponds. In the Botanic 

 Garden, in Edinburgh, and the tanks of the Zoolo- 

 gical Society, in Regent's Park, London, this plant 



