the area of cytoplasm , nucleus , nucleolus and mitochondria , as well as the elongation and irregular outline of the nucleus were determined , on electron micrographs by using an image analyser , for ap ( pale ) , ad ( dark with intranuclear vacuole ) , ad-like ( dark without intranuclear vacuole ) , ac ( cloudy ) and al ( long ) human spermatogonia .
C0007609
nucleolus
C0007610
nucleus