CHARA. VALLISNERIA. 435 



Chara may be placed, either with clean water alone, or a little earth 

 may be sprinkled over it, so as to keep it at the bottom ; or the bottom 

 may be covered one inch with closely-pressed mould, in order that the 

 water may be put in without disturbing it. On this lay the Chara, 

 with a little earth over the lower ends to fix it. The vessels kept in- 

 doors have a film which is always forming on the water, and which re- 

 quires to be frequently removed. By letting the water overflow the 

 surface becomes skimmed, though dipping out gently will do ; but in all 

 cases of pouring in water, hold something, such as a saucer or flat piece 

 of wood, to receive the pouring, and make it spread, instead of allowing 

 it to descend at once on the surface. Pans in the open air nearly full 

 of water will be kept in order by the wind and rain ; only take care to 

 supply the deficiency (the effect of evaporation), and to change some of 

 the water if it is considered necessary. 



Imitate the equal temperature of its native holes, by sinking the 

 pan a short way in the earth ; but during frosty weather keep the pan 

 wi thin-doors, and at the lower part of the house, as this situation is 

 generally the most uniform in its temperature. 



The Chara will live in any temperature above freezing, and grows 

 quicker as the warmth increases ; but above the earth, as outside of a 

 first-floor window, it will not bear the daily difference between the 

 mid-day sun and the cold of sun-rising. The glass jars I keep within 

 the house as nearly uniform in warmth as convenient. Similar care is 

 requisite for Vallisneria ; but the warmest and most equal temperature 

 is better suited to this plant. It should be planted in the middle of 

 the jar in about two inches deep of mould, which has been closely 

 pressed ; over this place two or three handfuls of leaves, then gently 

 fill the jar with water. When the water requires to be changed, a 

 small portion is sufficient to change at a time. It appears to thrive 

 in proportion to the frequency of the changing of the water, taking 

 care that the water added rather increases the temperature than 

 lowers it." 



The natural habitat of the Frog-bit is on the surface of ponds and 

 ditches ; in the autumn its seeds fall, and become buried in the mud 

 at the bottom during the winter ; in the spring these plants rise to 

 the surface, produce flowers, and grow to their full size during summer. 

 Chara may be found in many places around London, the Isle of Dogs, 

 and in ditches near the Thames bank. 



TJie New Water-weed (Anacharis alsinastrum). This remarkable 

 plant has recently made its appearance in the rivers Ouse and Cam. 

 It is so unlike any other water-plant, that it may be at once recognised 



