414 PRACTICAL BOTANY 



It lias been ascertained that numerous nuclei are present in the 

 mature internodal cells, and they are derived by fragmentation 

 from the original nucleus : evidence of this may be obtained from 

 stained preparations. 



IV. The cells of the Characese are well known as 

 good material for showing the movements of protoplasm 

 in the living cell : observations of this are to be made 

 on living specimens mounted in water. Nitella may be 

 used, or the naked terminal cells of the leaves of Cham. 

 Note that the chlorophyll granules, which lie in the 

 outer band of protoplasm, are stationary : the colourless 

 protoplasm below shows however movements by which 

 the granules and clots are carried along, so that a 

 rotation takes place round the large central vacuole. 

 If the movements be sluggish they may be accelerated 

 by gently warming the slide. Note especially the 

 movements in opposite directions on either side of the 

 neutral line, also the relative movements of the contents 

 of adjoining cells. 



V. In order to see the rhizoids, which fix the plant 

 at its base, remove one of the lowest nodes of an old 

 plant : wash it gently from mud, &c., and mount in 

 water : numerous long, transparent threads will be 

 seen to spring from the node : these are the rhizoids. 

 Observe their smooth wall, and granular protoplasm 

 with central vacuole, and the more or less obvious 

 nucleus. Here and there they branch, the point of 

 branching being marked by an oblique, and peculiarly 

 curved cell-wall : from a swelling above the septum 

 the branch-rhizoids spring. 



There are various modes of vegetative propagation of the 

 CharacesB, by means of peculiar forms of branching at the nodes : 



