Aquarium Plants 89 



from the other leaves. Salvinia natans is 

 an annual. It forms spores, which, during 

 the winter, rest on the bottom of the aqua- 

 rium, from which they can be removed with 

 some of the soil or sand, to be kept in a 

 separate glass for spring germination. 

 With sunlight and a fairly high temperature 

 it may be possible to hibernate some of the 

 plants until spring", when they will grow 

 rapidly. 



Moss-fern (Salvinia auricidata) grows wild 

 in North America. It is a very graceful 

 annual of moss-like appearance, growing 

 best in a covered aquarium, where it not 

 only fills the surface of the water but runs 

 up the rocks as far as they remain moist. 

 Its color varies according to the light, from 

 green to different shades of pink and even 

 red. This plant has to be renewed or raised 

 from spores every year. 



Floating Riccia (Riccia ftuitans) is, like 

 the previous plant, cryptogamous, — which 

 means that the sexual organs are not dis- 



