THE PLANT AND ITS ENVIRONMENT d 
require. Animals, on the other hand, must either move about 
in search of food or have it brought to them, as is the case with 
many marine animals whose food comes to them in the water. 
This difference in the method of obtaining food appears to be 
responsible for many of the distinctions between the more com- 
plex plants and animals. 
Roots. The roots of most plants are in the ground, although 
there are many plants, particularly in the tropics, which grow 
on other plants or on rocks 
and have their roots in the 
air (Fig. 2). The chief func- 
tions of the roots are to absorb 
water and mineral matter 
and to hold or anchor the 
plant in place. 
Stems. T’he stem serves 
as a support for the leaves, 
flowers, and fruits; for the 
transport of water and min- 
eral matter from the roots 
to the leaves and other or- 
gans; and for conducting 
manufactured food from the leaves to other parts of the plant. 
Flowers. In the flowers, male and female elements unite in 
sexual reproduction, a process which is very similar in both 
plants and animals. This process in plants is dependent on the 
transfer of small yellow grains called pollen, from sacs known 
as anthers, to the pistils, which contain the female elements 
known as eggs. The pollen is in many cases transferred by 
wind, or by insects which are attracted by the color or odor of 
the flowers. 
The various parts of the flower of an eggplant are shown in 
Fig. 3. In the drawing the flower is represented as split down 
one side to show the different organs. The conspicuous ex- 
panded part is the corolla. In the center is the pistel, composed 
of a basal portion, the ovary; a terminal portion, the stigma; 


Fig.3. A flower of an eggplant, split to 
show parts. (x 14) 
