126 CELLS AND TISSUES 
thoroughly modified for protection, absorption, strength, conduc- 
tion, food-making, etc., in most cases growth and division ceases. 
This brings us to the tissues which are groups of cells so modified 
as to be adapted to special functions and upon which the various 
activities of the plant depend. 
General View of Tissues 
The most important tissues of Seed Plants are those which have 
to do with growth, protection, support, conduction, secretions, 
absorption, food manufacture, food storage, and reproduction. 
Fic. 111. — A, lengthwise section through a tip of a stem, showing the 
apical meristem (m) from which branches (b) are arising and from which cam- 
bium (c) and other tissues are being formed below. B, cross section of a 
stem, showing the cambium and its position in reference to other tissues. 
Tissues Connected with Growth. — Since the cells of most tis- 
sues are no longer capable of growth and division after completing 
their modifications, there must be provided at certain places in 
the plant groups or bands of cells which retain their ability to 
grow and divide throughout the life of the plant, for otherwise 
the growth of the plant would soon cease. Such cells, forming 
the meristematic tissues or meristems (from the Greek word mean- 
ing ‘‘to divide’’), are preSent at the stem and root tips and in the 
cambium, where their chief function is the multiplication of cells, 
