Illumination The specimen will only be seen if the light passing through it, or reflected from it, travels up the tube of the microscope, to the eyepiece, and into your eye.
(The specimen; will only be seen; ) (the light passing through it; reflected; from it) (the light passing through it, or reflected from it; travels up; the tube of the microscope)
The specimen the light passing through it the light passing through it, or reflected from it
will only be seen reflected travels up
from it
the tube of the microscope