The existence of a hatching stimulant was comfirmed in the aqueous extract of the ultrasonically broken egg of the soybean cyst nematode, Heterodera glycines ICHINOHE. It was suggested that the agent is organic and water soluble, but hardly soluble in organic solvents such as benzene, hexan, ether, ethyl acetate, chloroform and methylene chloride. The activity of the agent was not inhibited at a temperature of 120°C for 30 min.
