XX.—The Phase of the Nucleus known as Synapsis

Abstract

That phase of the nucleus just preceding the heterotype mitosis, and which was first called Synapsis by Moore (1895), has come to be regarded as an important and critical period in the life-cycle. It was called synapsis because of the apparent condensation and contraction of the chromatin at one side of the nuclear cavity. This discovery at first received scant support, the synaptic contraction being considered by many investigators to be nothing more than an artifact—an artificial contraction caused by imperfect fixation. In 1897, however, Moore's discovery was confirmed by Miss Sargant, who not only observed it in fixed material, but also found it in the living pollen-mother-cells of Lilium.