108 
WORLD OF INVISIBLE LIFE 
What does hair 
loo\ like under 
a microscope? 
The bulb is deeply embedded in the skin and 
from its bottom grow fine nerves and blood 
vessels which nourish it. We never pull all this 
root out. Some of it remains in the skin and 
from it grows a new hair which is invisible at 
first but slowly pushes its way through the skin 
to the surface. The inner portion of this bulb, 
or root, is the true living portion of the hair 
which grows. The long thin hair above the 
skin is dead. It consists of a long thin tube filled 
with air. The tube also contains grains of red, 
brown, yellow, or black coloring matter, which 
is called pigment. This pigment is what gives 
the hair its color. It usually disappears with 
age and the hair grows gray and then white. 
The outside of the hair, which looks perfectly 
smooth to us, under the microscope has innu¬ 
merable wavy cross-lines on it. The hair of 
a cat, dog, rabbit, or any other animal is even 
rougher looking than human hair. It has all 
sorts of fine crisscross and zigzag lines on it so 
that sometimes it even looks like a bamboo or 
a palm tree trunk. A person who has studied 
