PRACTICAL BOTANY 



cap, dividing up by regularly arranged walls into a mass of 

 regular cells. 



b. Those cut off from the sides of the apical cell form the 

 body of the root : these also divide by walls in regular suc- 

 cession. Observe carefully the arrangement of these walls, and 

 by comparison of several sections ascertain their order of 



jy 



ST. 



? 3 z t 



FIG. 13. Diagram illustrating the arrangement of cell-walls as seen in a median 

 longitudinal section through the apex of the root of a Fern. /. ///. &c. indicate 

 segments cut off from the sides of the apical cell, which go to form the body of 

 the root ; , /, m, n, p, are successive segments from its base, which go to form 

 the root-cap. (After Goebel.) 



succession, and their relation to the various tissues of the root 

 above described. 



XIV. Cut successive transverse sections of the apex of a root 

 which has been hardened in alcohol : this may easily be done 

 if the root be held between pieces of pith, or better by em- 

 bedding in paraffin. If possible, keep all the sections in their 

 proper order of succession, and mount in glycerine. Examine 

 with a low power, and choose out those in which the large 

 apical cell is to be seen. Observe carefully 



I. The form of the apical cell, apparently three-sided: 



