PRODUCTION OF CLEAVAGE BY SUPPRESSION OF THE POLAR BODIES IN ARTIFICIALLY ACTIVATED EGGS OF URECHIS

Abstract

1. The polar bodies can be suppressed in artificially activated eggs of Urechis by means of a second treatment with dilute sea water. 2. The treatment must be applied before the time of extrusion of the first polar body and continued until after the time of extrusion of the second. 3. The eggs in which the polar bodies are thus suppressed undergo cleavage whereas ordinarily they would not do so. 4. Similar second treatments applied after the time of the extrusion of the second polar body do not induce cleavage.