ai 
40 PHARMACEUTICAL BOTANY 
in the inner layer of cytoplasm are carried along by the moving 
cytoplasm. In some plants like Nitella the nucleus is carried 
along with the current. (See Fig. 21.) 
4. Cytoplasmic circulation or streaming may be seen in the cells 
of the stamen hairs of the Spiderwort, in some epidermal cells of 
the onion and in the epidermal hairs of the squash. Here the 
cytoplasm will be seen in several strands traversing the cell 
cavity as well as lining the inner face of the cell wall. The 
Fic. 21.—Protoplasmic movement. 1 and 2, nuclei from the tapetal plas- 
modium of the spore case of Botrychium, 1, in the usual form, and 2, flattened while 
entering a crevice between spore-groups; 3, cell from Nitella showing cytoplasmic 
rotation as indicated by the arrows; 4, cell from stamen-hair of the Spiderwort 
(Tradescantia), showing circulation of the cytoplasm as indicated by the arrows. 
(After Stevens.) 
cytoplasm moves to and from the nucleus and cell wall and may 
after streaming in one direction for awhile, reverse itself. 
PROTOPLASMIC CELL CONTENTS 
The name “Protop.ast” has been given to the entire living 
or protoplasmic matter within a single cell. The protoplast 
consists of six well-differentiated portions, viz.: 
(a) Tue Cytop.asm, or the foamy, often granular matrix 
of protoplasm outside of the nucleus. Embedded in the cyto- 
plasm are non-protoplasmic bodies called inclusions. The most 
prominent of these are the vacuoles which are spaces within the 
cytoplasm containing either a watery solution of nourishing 
materials (cell sap) or, in old cells, air. 
