﻿438 ELEMENTARY BIOLOGY. [CHAP. 



each cell; the position of these granules, in 

 the more superficial layer of the protoplasm. 



<$. The protoplasmic movements (see C. a.). 



c. The terminal bud. 



Dissect out chromic acid specimens as far as pos- 

 sible with needles, and then press gently out in 

 glycerine. Note in different specimens 



a. The terminal or apical cell : 



a. Its form: hemispherical, the rounded surface 

 free; the flat surface attached to the cell 

 below it. 



fi. Structure : sac, protoplasm, nucleus; no vacuole- 

 present. 



y. Sometimes two nuclei, preliminary to division. 



8. Its mode of division; across the long axis of 

 the stem, giving rise to two superimposed 

 nucleated cells. 



b. The further fate of the new cells derived from 

 the segments of the terminal cell; work back in 

 your specimens from the terminal cell 



a. The new cells are successively nodal and inter- 

 nodal ; the latter enlarge, develope a large 

 vacuole, and ultimately form the medullary 

 cells of the internodes; they never divide. 



ft. The nodal cells divide freely, and do not 

 increase much in size ; they give origin to the 

 nodes and the cortical cells. 



c. The development of leaves: by the multiplication 



and outgrowth of nodal cells. 



