THE GENERAL STRUCTURE OF PLANTS 5 
filled with a watery fluid. In the multicellular plants each 
chamber during life contains its own protoplast or little mass 
Fic. 5.—VEGETABLE CELLS, 
A, very young; B, a little older, showing commencing formation of vacuole. 
p, protoplasm ; n, nucleus; v, a vacuole, 
of protoplasm, which is connected, as already mentioned, 
with its neighbours on all sides In such cavities the proto- 
plast when young usually occupies the whole of the interior 
(fig. 5, a), but when they are adult it generally lies as a 
peripheral layer round the wall, to 
which it is closely pressed, while a 
central vacuole occupies the greater 
space of the cavity enclosed by the 
cell- walls (fig. 6). Sometimes the 
vacuole is crossed by a number of 
bridles or strands of protoplasm, 
which generally pass from a some- 
what central spot to the periphery. 
The protoplasm is transparent, but 
somewhat granular in appearance, 
and is saturated with water. Some- 
where in its substance, whether it 
fills the cell-cavity or not, there 
exists a special differentiated por- 
tion called the nucleus. Sometimes, 
but only in particular cells, the pro- 
Fic. 6.—ADULT VEGETABLE 
Certs. x 600. (After 
Sachs.) - 
h, cell-wall; p, protoplasm ; 
k, k’, nucleus, with nu- 
cleoli; s s’, vacuoles, 
toplasm contains other differentiated portions, distinct 
from the rest of the substance, which are known as 
