SEX 
7 
the lower forms of life both ova and spermatozoa are pro¬ 
duced in the same organism. Such animals are called 
hermaph'rodites (Hermes, Aphrodite, the Greek names of 
Mercury and Venus). 
Common examples are 
sea anemones, some cor¬ 
als, most worms, and 
some snails. Though 
many flowers contain 
only one of the reproduc¬ 
tive cells in one individual 
plant and the other cell 
in another individual, 
most common plants con¬ 
tain both cells in the 
same flower and are said 
to be perfect, which means 
the same as hermaphro¬ 
ditic. In most common 
animals the ova are pro¬ 
duced in special organs 
called ovaries, found in 
the female only, and the 
spermatozoa are pro¬ 
duced in organs called 
spermaries or testes (tes'- 
tes), in the male only. 
This separation of ovaries 
and testes in different in¬ 
dividuals gives rise to 
sex, male and female. 
There is no such sex difference in hydra, sea anemones, 
earthworms, and such animals. 
1. What is the fundamental difference between a male and a 
female? 
Figure 8. • 
Common Cell Division in 
Growth. 
In the second stage the star-like central 
body has divided in two and the color 
bodies are becoming distinct. In the third 
stage the central bodies have taken their 
position in opposite poles of the cell and 
the color bodies have divided, keeping the 
original number. In the fourth stage the 
color bodies are gathering at the poles. In 
the fifth stage a constriction is beginning 
to divide the cell. In the sixth stage the 
division is complete. 
