LECTURE II. 
CELLS. 
In the first Lecture it was stated that the most 
simple plants are composed of cells or utricles, and that 
all others, however complicated in structure, are made 
up of a series of such cells, variously modified by pres- 
sure, and arranged according to the conditions under 
which they are developed and the functions they have to 
perform. Within the transparent membrane of which 
the young cell alone consists, there is in the growing 
cell a thin delicate lining, termed the primordial utricle 
of Mohl ; within this is a nucleus or cytoblast, and this 
again contains smaller cells or nucleoli. The typical form 
of the cell is either spherical or oval ; but by pressure 
in growth, cells assume almost every variety of shape, 
and their walls become thickened either uniformly or 
partially. In the most lowly organized plants among 
the Algce and Fungi , the cells maintain their original 
form throughout life ; but in the majority of instances, 
c 
