14 THE AQUARIUM. 



It must not be inferred that we advise the introduction 

 of all these species into one aquarium ; two or three 

 species is sufficient. Of these, one species chosen should 

 have floating leaves, to afford cool shade for the fishes, 

 &c. The first named of these, the American Pondweed, 

 is a very rapid grower, and the smallest piece of it will 

 develop roots and quickly attain a considerable length. 

 It consists of a long brittle stem upon which the bright 

 green leaves are arranged in whorls of threes, as in Fig. 4<^. 

 It is to be found in almost every pond and stream in the 



kingdom. A somewhat similar but 

 less robust-looking species is the 

 Water Starwort {CallitricJie verna), 

 in which the stem is more sparsely 

 clothed with leaves, and at the 

 growing extremity the leaves form 

 a flat star-like head, from which 

 the plant derives its popular name. 

 The Water Crowfoot is one of the 

 buttercup family, but its flowers are 

 white, the petals tinted with yellow 

 ^, ^ ^. near the centre of the flower. It 



The Frogbit. 



is a tolerably robust species, and, 

 as its flowers are floating ones, presents a very pretty 

 appearance. The Frogbit is desirable on account of its 

 floating heart-shaped leaves, which afford a little shade 

 to various of the inhabitants. One of the most favourite 

 plants for the aquarium is the Vallisneria spiralis, a plant 

 not found wild in England, but easily to be obtained 

 from any of the dealers in aquarium requisites. 



Our next consideration is the finny denizens of our 

 mimic pond. Before deciding what fish we are to 

 introduce, we must settle whether the water is to be 



