EFFECTS OF BENZIMIDAZOLE ON CLEAVAGE OF THE SEA URCHIN EGG.

Unfertilized eggs of sea urchins were treated with benzimidazole. They were fertilized after being kept in normal sea water for a certain period. It was found that the first cleavage occurred much earlier than in the control. The eggs had a tendency to cleave directly into 3 or 4 cells. Benzimidazole induced some visible changes in unfertilized eggs, which was considered to be the result of an insufficient activation. Benzimidazole was found to have the same effect as hypertonic solution has in Loeb's "double treatment" method for artificial parthenogenesis. When eggs activated with butyric acid were treated with benzimidazole instead of hypertonic solution, they cleaved in a high percentage.