CIRCULATION IN PLANTS. 381 



prominence exposed to the current. If the Chara could bear 

 a current, its fruit would mostly be carried on and be deposited 

 m holes; but it sends out from its various joints very fine long 

 roots into the water, and these would by agitation be destroyed, 

 and then the plant 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, there- 

 fore, to preserve Chara, every care must be taken to imitate 

 the stillness of the water, by never shaking or suddenly turn- 

 ing 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. 



" Secondly. Imitate the freshness of the water, by having 

 an extent of surface, which it is requisite to skim frequently, 

 or suffer it to overflow by the addition of more water. These 

 precautions being attended to, a clear bright surface is kept. 

 It is also desirable to cha,nge a small portion of the water, but 

 this should be done without agitation. The best vessels for 

 cultivating this plant in, are either wide pans, holding three 

 or four gallons, or glass jars a foot or more high ; into these 

 the 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 httle earth over 

 the lower ends, to fix it. Causing the water to overflow is 

 the readiest way to skim the surface, 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 taking care to 

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

 some of the water, if it be considered necessary. The vessels 

 kept in-doors have a film which is always forming on the water, 

 and which requires to be frequently removed. 



