438 ELEMENTARY BIOLOGY. [CHAP. 



each cell; the position of these granules, in 

 the more superficial layer of the protoplasm. 



8. 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. 



/S. Structure: cell- wall, 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 i?iter- 

 nodal^ one nodal and one internodal cell being 

 formed from each segment; the internodal 

 cells enlarge, develope a large vacuole, and ul- 

 timately form the medullary cells of the inter- 

 nodes ; they never divide. 



)8. 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. 



