Fig. 54. Th e Relation of M itosis and Meiosis (according to Darlington).—The stages of mitosis are shown on the left, and the corresponding stages of meiosis on the right. Note that the chromosomes are double at their first appearance in mitosis, but not in the earliest (leptotene) stage of meiotic prophase. They pair in zygotene, beginning to become double (split) in pachytene, and are double in the last stages of meiotic prophase (diplotene and diakinesis). In mitosis anaphase begins by the division of the centromeres, but in meiosis this does not occur till the anaphase of the second division (not shown).