THE CELI,. 



159 



Sk I f 

 Pig. 218. 



granular appearance, and in the centre of each a rounded 

 denser portion may be made out, each of these again 

 enclosing one or more smaller bodies. This liquid which 

 I thus fills the newly-formed cells is 



V*- ^W^ J calledjjroioptem; the large rounded 

 -f "'"^ ^^ V central mass is the nucleus, consist- 

 '^ "-^^ ^^-^ /" '^"^ °* denser protoplasm, and the 

 '"'^i ■? f*'^ ' smaller enclosed masses are the 

 "^ ' , i^'x , nucleoli. 



Ifow let us consider Fig. 219. 

 This is a representation of a section 

 of the same rootlet, taken a little 

 farther back from the point, so 

 that the cells now in view are a 

 little older than the first ones. 

 They are manifestly larger ; that 

 is to say, they have grown. The 

 nucleus and the nucleoli can still 

 be made out in some of them, but 

 the protoplasm no longer entirely 

 fills the cell. There are now 

 transparent - spaces (vacuoles) 

 which are filled with water, and 

 between these the protoplasm is 

 seen in the form of strings or 

 bands, as well as lining the cell. pip. 219. 



The water has been absorbed through the cell-wall, and 

 after saturating the protoplasm the excess has formed the 

 vacuoles. 



Fig. 218.— Young cells filled with protoplasm (p) ; i, cell wall ; h, nucleqs ; 

 Jch, nucleolus. (Sachs.) 

 Fig. 219.— Cells » little older, exhibiting vacuoles (s), {Saofts,) 



