CHARA. 321 



decays ; for although it may grow long before roots are 

 formed, yet when they are produced their destruction 

 involves the death of the plant. In order, therefore, to 

 preserve Chara, every care must be taken to imitate the 

 stillness of the water by never shaking or suddenly turning 

 the vessel. It is also important that the Chara should be 

 disturbed as little as possible ; and if requisite, it must 

 be done in the most gentle manner, as, for instance, in 

 cutting off a specimen, or causing it to descend in order 

 to keep the summit of the plant below the surface of the 

 water. 



Similar care is requisite for Vail isneria; 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-hit, another water- 

 plant of great interest, 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. 



Anacharis alsinastrum. — This remarkable plant is so 

 unlike any other water-plant, that it may be at once 

 recognised by its leaves growing in threes round a slender 

 stringy stem. The watermen on the river have already 

 named it " Water-thyme," from a faint general resemblance 

 which it bears to that plant. In 1851 the Anacharis 

 was noticed by Mr. Marshall and others in the river 

 at Ely, but not in great quantities. Next year it had 

 increased so much, that the river might be said to be full 

 of it. 



The colour of the plant is deep green ; the leaves are 



Y 



