168 ABOUT HORSETAILS, [CHAP. 
The nodal cells give rise to the branches and whorled 
appendages, and to the organs 
of reproduction. Fig. 122 is 
a diagram of a_ longitudinal 
section through the plant, and 
will serve to show the relative 
size and position of these cells. 
A.C. shows the large axial cells, 
separated by N.C., the nodal 
cells, and invested by C.C., the 
cortical cells. Fig. 123 isacross 
section in which A represents 
the axial cell, B the cortical cells. 
The most remarkable feature in Chara is what is 
known as its protoplasmic movements, If a portion 
of the plant be placed under the microscope, and a 
low-power objective used, these movements may be 
seen distinctly. If the focussing be adjusted so as to 
bring out the large axial cell, and observed carefully 
for a few seconds, the granules of proto- 
A, plasm will be seen slowly, but uninter- 
fe ruptedly, to stream up one side of the 
cell and down the other. Similar move- 
ments in the protoplasm of cells may be 
seen in the American Pond-weed (Axacharis alsinas- 
trum), Vallisneria spiralis, and in the hairs of Nettle 
and Tradescantia. 
From the axils of the whorled appendages Chara 
produces two orange-coloured bodies—the antheridia 
and sporangia. The sforangium is an oval cell in- 
vested by five rows of spirally-twisted cortical cells, 
so arranged as to leave an aperture at the summit, 
Fic. 122. 
Fic. 123. 
