50 ELEMENTARY BIOLOGY. [CHAP. 



uncoloured band round 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. 

 /?. Structure: sac, protoplasm, nucleus ; no vacuole 



present. 



y. Sometimes two nuclei; preliminary to division. 

 3. 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 which are 

 successively segmented off from 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. 



